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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.
311

Biološka aktivnost i hemijski sastav ekstrakata odabranih autohtonih makrogljiva / Biological activity and chemical caracteristics  of selected extracts of  autochtonous macrofungi

Janjušević Ljiljana 18 September 2017 (has links)
<p>Prema postavljenim ciljevima u ovoj doktorskoj disertaciji sakupljeno je i&nbsp;<br />determinisano&nbsp;ukupno&nbsp;sedam&nbsp;vrsta&nbsp;autohtonih&nbsp;gljiva&nbsp;sa&nbsp;područja&nbsp;Fru&scaron;ke&nbsp;gore, Tare i&nbsp; Vr&scaron;ačkog brega, pet lignikolnih&nbsp;‐&nbsp;<em>Bjerkandera adusta</em>,&nbsp;<em>Pleurocybella&nbsp; porrigens</em>,&nbsp;St<em>ereum&nbsp;hirsutum,&nbsp;Stereum&nbsp;subtomentosum</em>&nbsp;i&nbsp;Trametes&nbsp;versicolor,&nbsp;i&nbsp;<br />dve&nbsp; terikolne&nbsp;‐&nbsp;<em>Amanita&nbsp; strobiliformis</em>&nbsp;i Hydnum repandum. Utvrđena je&nbsp; njihova&nbsp;biolo&scaron;ka&nbsp;aktivnost&nbsp;(antiradikalska,&nbsp;antioksidativna,&nbsp;antimikrobna,&nbsp;anti‐acetilholinesterazna&nbsp;i&nbsp;citotokisčna)&nbsp;spram&nbsp;hemijskog&nbsp;sastava&nbsp;njihovih&nbsp;vodenih&nbsp;<br />(H<sub>2</sub>O),&nbsp;etanolnih&nbsp;(EtOH),&nbsp;metanolnih&nbsp;(MeOH)&nbsp;i&nbsp;polisaharidnih&nbsp;(PSH)&nbsp;ekstrakata.&nbsp;<br />Analiza&nbsp;hemijskog&nbsp;sastava&nbsp;odabranih&nbsp;vrsta&nbsp;uključila&nbsp;je&nbsp;određivanje&nbsp;hemijske&nbsp;<br />karakterizacije&nbsp;PSH&nbsp;ekstrakata&nbsp;‐&nbsp;FTIR&nbsp;analizom,&nbsp;određivanje&nbsp;fenolnog&nbsp;profila&nbsp;‐&nbsp;<br />HPMC/MS‐MS,&nbsp;sadržaja&nbsp;organskih&nbsp;kiselina&nbsp;‐&nbsp;HPLC,&nbsp;sadržaja&nbsp;masnih&nbsp;kiselina&nbsp;‐&nbsp;<br />GC‐FID&nbsp;i&nbsp;sadržaja&nbsp;biogenih&nbsp;elemenata&nbsp;‐&nbsp;AAS.&nbsp;Spektrofotometrijskim&nbsp;metodama<br />određen je ukupan sadržaj proteina i ukupan sadržaj fenola i flavonoida.&nbsp;<br />Prema&nbsp;antiradikalskoj&nbsp;aktivnosti&nbsp;OH<sup>&bull; ,&nbsp;</sup>O2<sup>&bull;‐</sup>,&nbsp;OH<sup>&bull;</sup>,&nbsp;Asc<sup>&bull;</sup>,&nbsp;DPPH<sup>&bull;&nbsp;</sup> i&nbsp;ABTS<sup>&bull;+</sup>&nbsp;izdvojili&nbsp;<br />su&nbsp; se&nbsp; ekstrakti lignikolnih vrsta:&nbsp; MeOH ekstrakt vrste&nbsp;<em>P. porrigens</em>, H<sub>2</sub>O&nbsp; ekstrakt&nbsp;<em>P.&nbsp;porrigens</em>,&nbsp;MeOH&nbsp;ekstrakt&nbsp;<em>T.&nbsp;versicolor</em>,&nbsp;H<sub>2</sub>O&nbsp;ekstrakt&nbsp;<em>S.&nbsp;hirsutum, </em>MeOH&nbsp;ekstrakt&nbsp;<em>S.&nbsp;subtomentosum</em>&nbsp;i&nbsp;H<sub>2</sub>O&nbsp;ekstrakt&nbsp;<em>B.&nbsp;adusta</em>,&nbsp;navedenim&nbsp;redom.&nbsp;<br />Najjaču antioksidativnu aktivnost dobijenu FRAP i polarografskom HPMC&nbsp;<br />metodom ispoljili su PSH i H<sub>2</sub>O ekstrakti terikolne vrste&nbsp;<em>A. strobiliformis</em>.&nbsp;<br />Antimikrobna aktivnost analiziranih ekstrakata određena je ispitivanjem&nbsp;<br />antibakterijskog,&nbsp;antifungalnog&nbsp;i&nbsp;antiviralnog&nbsp;potencijala,&nbsp;pri&nbsp;čemu&nbsp;se&nbsp;izdvojila&nbsp;<br />vrsta&nbsp;<em> H.&nbsp; repandum</em>&nbsp;ispoljavajući najbolji efekat na Gram‐pozitivne i Gram‐<br />negativne bakterije i na sve analizirane fitopatogene izolate&nbsp;<em>(Fusarium&nbsp;</em>i&nbsp;<br />Alternaria)&nbsp;i<em>&nbsp;T.&nbsp;versicolor</em>&nbsp;na&nbsp;analizirani&nbsp;bakteriofag.&nbsp;Anti‐acetilholinesterazna&nbsp;<br />aktivnost određena je testovima in solid i in liquid, a najbolji procenat&nbsp;<br />inhibicije AChE ispoljili su EtOH ekstrakti vrsta&nbsp;<em>S. hirsutum</em>,&nbsp;<em>B. adusta</em>,&nbsp;<em>S</em>.&nbsp;<br /><em>subtomentosum</em>&nbsp;i&nbsp;<em>T.&nbsp;versicolor</em>.&nbsp;Citotoksična&nbsp;aktivnost&nbsp;ekstrakata&nbsp;određena&nbsp;je&nbsp;<br />MTT testom, a prema najboljoj ispoljenoj aktivnosti izdvojili su se MeOH&nbsp;<br />ekstrakt<em>&nbsp;P.&nbsp;porrigens&nbsp;</em>i&nbsp;ekstrakti<em>&nbsp;B.&nbsp;adusta</em>,&nbsp;H<sub>2</sub>O&nbsp;i&nbsp;EtOH.&nbsp;Citotoksična&nbsp;aktivnost&nbsp;<br />ovih&nbsp;lignikolnih&nbsp;vrsta&nbsp;naročito&nbsp;je&nbsp;izražena&nbsp;nakon&nbsp;72&nbsp;h.&nbsp;Na&nbsp;osnovu&nbsp;dobijenih&nbsp;<br />rezultata, gde su se istakle različite vrste i njihovi različiti ekstrakti u&nbsp;<br />primenjenim&nbsp;testovima,&nbsp;jasno&nbsp;je&nbsp;da&nbsp;biolo&scaron;ka&nbsp;aktivnost&nbsp;i&nbsp;hemijski&nbsp;sastav&nbsp;zavise&nbsp;<br />od&nbsp;porekla,&nbsp;vrste&nbsp;i&nbsp;tipa&nbsp;ekstrakta&nbsp;analiziranih&nbsp;gljiva.&nbsp;Na&nbsp;osnovu&nbsp;tipa&nbsp;rastvarača&nbsp;<br />odnosno ekstrakata vrsta, koje su pokazale najbolju aktivnost spram pomenutih&nbsp; testova i na osnovu dobijenih korelacija kao i na osnovu detektovanih jedinjenja,&nbsp; pretpostavljamo da su za ispoljene aktivnosti u najvećoj meri odgovorna fenolna&nbsp; jedinjenja&nbsp;i&nbsp;polisaharidi.&nbsp;&nbsp;<br />&nbsp;<br />Ispoljeni&nbsp;biopotencijal&nbsp;analiziranih&nbsp;vrsta&nbsp;gljiva&nbsp;upućuje&nbsp;na&nbsp;njihovu&nbsp;potencijalnu&nbsp;<br />upotrebu kao funkcionalne hrane i nutraceutika, kao i u biokontroli&nbsp;<br />fitopatogena.</p> / <p>According&nbsp; to&nbsp; the&nbsp; set&nbsp; aims&nbsp; of&nbsp; the&nbsp; presented&nbsp; PhD&nbsp; thesis,&nbsp; seven&nbsp; autochthonous fungal species from the region of Fruska Gora, Tara&nbsp; and Vr&scaron;ac Mountains were collected and determined: five lignicolous ‐ <em>Bjerkandera&nbsp; adusta,&nbsp; Pleurocybella&nbsp; porrigens,&nbsp; Stereum&nbsp; hirsutum,&nbsp; Stereum subtomentosum and Trametes versicolor</em>, and two terricolous ‐ <em>Amanita strobiliformis </em>and <em>Hydnum repandum</em>. Biological activity of these&nbsp; species&nbsp; (antiradical,&nbsp; antioxidant,&nbsp; antimicrobial,&nbsp; anti‐ acetylcholinesterase and cytotoxic) was determined in relation to the chemical composition of the extracts, aqueous (H<sub>2</sub>O), ethanolic (EtOH), methanolic (MeOH) and polysaccharide (PSH). Analysis of the chemical content of analyzed species included chemical characterization of PSH extracts&nbsp; &ndash;&nbsp; by&nbsp; FTIR&nbsp; analysis,&nbsp; determination&nbsp; of&nbsp; phenolic&nbsp; profile ‐ by HPMC/MS‐MS, content of organic acids ‐ by HPLC, fatty acid content ‐ by&nbsp; GC‐FID&nbsp; and&nbsp; content&nbsp; of&nbsp; biogenic&nbsp; elements ‐ by&nbsp; AAS. Spectrophotometric methods were applied for determination of the content of total proteins, polyphenols and flavonoids. According to the antiradical activity obtained towards OH<sup>&bull;</sup>, О2<sup>&bull;‐</sup>, OH<sup>&bull;</sup>, Asc<sup>&bull;</sup>, DPPH<sup>&bull;</sup>&nbsp;and ABTS<sup>&bull;+</sup> extracts of lignicolous species were singled out: <em>P. porrigens&nbsp;</em> (MeOH&nbsp; extract),&nbsp;<em> P.&nbsp; porrigens</em>&nbsp; (H<sub>2</sub>O&nbsp; extract),&nbsp;<em>T. versicolor</em>&nbsp;(MeOH&nbsp;&nbsp; extract),<em> S. hirsutum </em>(H<sub>2</sub>O extract), <em>S. subtomentosum</em> (MeOH extract) and&nbsp;<em>B. austa</em> (H<sub>2</sub>O&nbsp; extract),&nbsp; respectively. The&nbsp; highest antioxidant activity obtained by FRAP and the polarographic HPMC method was exhibited&nbsp; for PSH&nbsp; and&nbsp; H<sub>2</sub>O extracts of the terricolous species&nbsp;<em>A. strobiliformis</em>. The intimicrobial activity of analyzed extracts was determined by examination of antibacterial, antifungal and antiviral potentials, whereby&nbsp; the species&nbsp; <em>H.&nbsp; repandum&nbsp;</em>was separated by exhibiting the best effect on Gram‐positive&nbsp; and Gram‐negative bacteria, and all the analyzed hytopathogenic isolates (<em>Fusarium, Alternaria</em>)&nbsp; and <em>T. versicolor</em>&nbsp;against analyzed bacteriophage. Anti‐cetylcholinesterase activity was determined by tests in solid and in liquid, while the best&nbsp; percent of AChE inhibition was showed by EtOH extracts of the species <em>S. hirsutum, B. adusta, S. subtomentosum </em>and <em>T. versicolor</em>.bThe cytotoxic activity of extracts was determined by MTT assay, and according to the best activity, the MeOH extract of <em>P. porrigens</em>, and H<sub>2</sub>O and EtOH extracts of <em>B. adusta</em>&nbsp;were distinguished particularly after 72 h. Based on the results obtained, favoring different species and their different extracts in the applied tests, it is clear that the biological activity and chemical composition depend on the origin, species and type of extract of the analyzed fungi. Based on the type of solvent or extract of the species that showed the best activity in relation to the above tests and on the basis of the obtained correlations as well as on&nbsp; the basis of the detected compounds, we assume&nbsp; that&nbsp; the&nbsp; phenol compounds&nbsp; and&nbsp; polysaccharides&nbsp; are responsible for the activities performed.<br />Demonstrated bio‐potential of analyzed fungal species indicates their&nbsp; potential use as functional foods and nutraceutics, as well as in the biocontrol of phytopathogens.</p>
312

Novel molecular mechanisms of neuronal and vascular protection in experimental glaucoma

Almasieh, Mohammadali 04 1900 (has links)
No description available.
313

Účinky multipotentních sloučenin ovlivňujících neurotransmisi ve farmakologických animálních modelech kognitivního deficitu / Effects of Neurotransmission-Modulating Multipotent Compounds in Pharmacological Animal Models of Cognitive Deficit

Chvojková, Markéta January 2021 (has links)
In preclinical research on Alzheimer's disease pharmacotherapy, attention is paid to multipotent compounds, enabling intensification of the effect by targeting multiple pathophysiological mechanisms. The aim of the thesis was to assess the effect of multipotent compounds and combination therapy in models of cognitive deficit in the rat. The mechanism of action of the tested compounds was modulation of neurotransmitter systems. The aim of the first part of the study was to compare the effect of experimental monotherapy and combination therapy with an N-methyl-D-aspartate (NMDA) receptor antagonist and a γ-aminobutyric acid type A (GABAA) receptor positive modulator in the trimethyltin-induced model. Superiority of the combination therapy was proven by histological analysis of hippocampal neurodegeneration; however, it did not reach statistical significance in the cognitive test. The other part of the thesis focused on multipotent tacrine derivatives. We demonstrated a positive effect of 6- chlorotacrine-6-nitrobenzothiazole hybrid, as well as 6-chlorotacrine-L-tryptophan hybrid, acting as acetylcholinesterase inhibitors, in the scopolamine-induced model of cognitive deficit. Besides, we demonstrated a low risk of serious side effects of other tacrine derivatives acting as NMDA receptor antagonists....
314

Fitohemijski skrining i biološka aktivnost ekstrakata i tradicionalnih proizvoda od plodova divljih ruža (Rosa L.;Rosaceae) / Phytochemical screening and biological activity ofextracts and traditional preserves of rose hips (Rosa L., Rosaceae)

Nađpal Jelena 13 July 2017 (has links)
<p>&nbsp;&nbsp; Cilj ove doktorske disertacije predstavljalo je ispitivanje fitohemijskog sastava i biolo&scaron;ke aktivnosti vodenih i metanolnih ekstrakata svežih i suvih plodova, kao i voćne ka&scaron;e i džema pripremljenih po tradicionalnoj recepturi od plodova &scaron;est samoniklih vrsta <em>Rosa L.: R. canina, R. dumalis, R. dumetorum, R. tomentosa, R. arvensis, R. sempervirens. </em>Ispitivanje fitohemijskog sastava obuhvatalo je LC -MS/MS analizu 64 odabrana fenolna jedinjenja, hinske kiseline (organske kiseline) kao i tri triterpenoida. Takođe, izvr&scaron;eno je spektrofotometrijsko određivanje sadržaja ukupnih fenolnih i flavonoidnih jedinjenja, kao i vitamina C. Evaluacija biolo&scaron;ke aktivnosti obuhvatala je in vitro ispitivanja&nbsp; antioksidantne i antiinflamatorne aktivnosti, kao i ispitivanje uticaja ekstrakata odabranih vrsta Rosa na aktivnost enzima acetilholinesteraze i rast tumorskih i netumorskih ćelija.</p><p>&nbsp;&nbsp; Sumiranjem dobijenih rezultata može se zaključiti da sveži i suvi plodovi ispitivanih vrsta <em>Rosa</em>, kao i voćne ka&scaron;e i džemovi predstavljaju značajan izvor vitamina C i fenolnih jedinjenja, sa elagnom kiselinom kao najzastupljenijom fenolnom komponentom. Takođe u pojedinim ekstraktima vrsta<em> R. dumetorum</em> i<em> R. tomentosa</em> detektovana je visoka koncentracija ursolne kiseline, dok je hinska kiselina prisutna u značajnoj koncentraciji u svim ispitivanim ekstraktima.</p><p>&nbsp; &nbsp;Ekstrakti ispitivanih vrsta, izuzev vrste<em> Rosa arvensis</em>, pokazali su visok antioksidantni potencijal koji se ogleda u njihovoj sposobnosti neutralizacije nekoliko radikalskih vrsta, redukcionom potencijalu i sposobnosti inhibicije lipidne peroksidacije. Ispitivani ekstrakti ispoljili su umerenu antiinflamatornu aktivnost u pogledu inhibicije produkcije odabranih metabolita ciklooksigenaznog (12-HHT, TXB<sub>2</sub>, PGE<sub> 2</sub>) i 12-lipooksigenaznog (12-HETE) metaboličkog puta arahidonske kiseline,&nbsp; posebno prostaglandina E&nbsp; . Takođe, in vitro ispitivanjem uticaja ekstrakata odabranih vrsta Rosa na aktivnost acetilholinesteraze pokazana je umerena aktivnost. Vodeni ekstrakti i ekstrakti voćnih ka&scaron;a vrsta <em>R. canina, R. tomentosa i R. sempervirens</em> pokazali su umereni inhibitorni potencijal prema rastu HeLa ćelijske linije, dok su ekstrakti vrste <em>R. sempervirens </em>pokazali aktivnost i prema HT-29 ćelijama. Dobijeni rezultati ukazuju na značajni potencijal plodova i tradicionalnih proizvoda ispitivanih vrsta <em>Rosa</em> za upotrebu u proizvodnji nutraceutika i funkcionalne hrane.</p> / <p>&nbsp;&nbsp; The aim of presented doctoral thesis was investigation of phytochemical composition and biological activity of water and methanol extracts of fresh and air-&nbsp; dried rose hips, as well as pur&eacute;e and jam made according to traditional recipe of&nbsp; hips of six wild growing<em> Rosa L. species: R. canina, R. dumalis, R. dumetorum, R</em>.&nbsp; <em>tomentosa, R. arvensis, and R. sempervirens.</em> Examination of phytochemical composition included LC-MS/MS analysis of 64 selected phenolic compounds, quinic&nbsp; acid (organic acid) and three triterpenoids. Also, total phenolic and flavonoid contents, as well as vitamin C contents were determined spectrophotometrically. Biological activity evaluation of extracts of six <em>Rosa</em> species included in vitro investigation of antioxidant, anti- inflammatory, anti-acetylcholinesterase and cytotoxic activity.<br />&nbsp;&nbsp; According to obtained results, fresh and air-dried rose hips, as well as their preserves present valuable source of vitamin C and phenolic compounds, especially&nbsp; ellagic acid, which was the most abundant examined phenolic compound. Furthermore, high concentration of ursolic acid was detected in some<em> Rosa &nbsp;</em> <em>tomentosa and R.&nbsp; rumetorum</em> extracts, while notable concentration of quinic acid&nbsp; was present in all examined extracts.<br />&nbsp;&nbsp; Extracts of all examined species, apart from <em>Rosa arvensis</em>, showed considerable antioxidant activity in terms of radical scavenging ability, reduction potential and inhibition of lipid peroxidation. Moreover, extracts exhibited moderate anti- inflammatory activity by means of inhibition of the main arachidonic acid metabolites &nbsp; formed incyclooxygenase-1 (12-HHT, TXB<sub>2</sub>, PGE <sub>2</sub> ) and 12-lipoxygenase (12-HETE)&nbsp; pathway, especially prostaglandin E<sub>2</sub> . Also, investigation of anti- cetylcholinesterase&nbsp; activity revealed moderate activity of extracts of all examined species. In addition,&nbsp; predominantly water extracts of fresh andair-dried rose hips, as well as pur&eacute;e of<em> R</em>.&nbsp; <em>canina, R. tomentosa </em>and <em>R. sempervirens</em> showed inhibitory activity toward HeLa, while <em>R.sempervirens</em> extracts also inhibited HT-29 cell growth. Presented results indicate significant potential of examined rose hips and their preserves for use as nutraceuticals and functional food.</p>
315

Characterization of Hepatitis C Virus Infection of Hepatocytes and Astrocytes

Liu, Ziqing January 2014 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Approximately 2.8% of the world population is currently infected with hepatitis C virus (HCV). Neutralizing antibodies (nAbs) are often generated in chronic hepatitis C patients yet fail to control the infection. In the first two chapters of this study, we focused on two alternative routes of HCV transmission, which may contribute to HCV’s immune evasion and establishment of chronic infection. HCV was transmitted via a cell-cell contact-mediated (CCCM) route and in the form of exosomes. Formation of HCV infection foci resulted from CCCM HCV transfer and was cell density-dependent. Moreover, CCCM HCV transfer occurred rapidly, involved all four known HCV receptors and intact actin cytoskeleton, and led to productive HCV infection. Furthermore, live cell imaging revealed the temporal and spatial details of the transfer process. Lastly, HCV from HCV-infected hepatocytes and patient plasma occurred in both exosome-free and exosome-associated forms and the exosome-associated HCV remained infectious, even though HCV infection did not significantly alter exosome secretion. In the third chapter, we characterized HCV interaction with astrocytes, one of the putative HCV target cells in the brain. HCV infection causes the central nervous system (CNS) abnormalities in more than 50% of chronically infected subjects but the underlying mechanisms are largely unknown. We showed that primary human astrocytes (PHA) were very inefficiently infected by HCV, either in the free virus form or through cell-cell contact. PHA expressed all known HCV receptors but failed to support HCV entry. HCV IRES-mediated translation was functional in PHA and further enhanced by miR122 expression. Nevertheless, PHA did not support HCV replication regardless of miR122 expression. To our great surprise, HCV exposure induced robust IL-18 expression in PHA and exhibited direct neurotoxicity. In summary, we showed that CCCM HCV transfer and exosome-mediated HCV infection constituted important routes for HCV infection and dissemination and that astrocytes did not support productive HCV infection and replication, but HCV interactions with astrocytes and neurons alone might be sufficient to cause CNS dysfunction. These findings provide new insights into HCV infection of hepatocytes and astrocytes and shall aid in the development of new and effective strategies for preventing and treating HCV infection.

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