• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 3
  • 1
  • 1
  • Tagged with
  • 5
  • 5
  • 3
  • 2
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 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

Studies on the Antioxidative Potential of the Freeze-Dry Extract (Tsan-Ron-Bau-Yuan) of Fruits and Vegetables, DNA Vaccine Against Mycoplasma hyopneumoniae

Wang, Hsiao-Ning 04 August 2000 (has links)
The oxidative damage to DNA, protein and lipid, may be accumulated and play a role in the process of human cell aging. Oxidative stress may be due to the aerobic respiration and ozone-induced radiation which result in reactive oxygen species known as free radicals. Therefore, the antioxidant and free radical scanvenger which may reduce the oxidative damage, are of great interest, both in academic research and in the business world. The present study aims to evaluate the antioxidative potential of a very unique vegetable-fruit extract (Tsan-Ron-Bau-Yuan). The extract consists of over forty domestic vegetables and fruits, without using chemical fertilizers and pesticides during their entire growth period, is produced through a sophisticated freeze-dry technology. The anti-hydroxyl radical antioxidative potential were evaluated using the following four methods: (1) the plasmid DNA (2) the protein (3) the cell line and (4) the red blood cell . The results clearly demonstrat that the aqueous fraction of this extract can remarkably reduce the oxidative damage as evidenced by the DNA and protein model. In addition, the susceptibility of human red cells to oxidative stress can also be alleviated to some extents based on the RBC deformability studies. The efficacy of protection of the oxidative damage mediated by .OH generated by the Fenton¡¦s reaction was in the order of : aquaeous extract >100% ethanol extract > ethanol/ethylacetatee extract > 50% ethanol extract. Conversely, no significant protection to the action of hydrogen peroxide was observed in the cell line. Lysozyme which is ubiquitous among various natural products has negligible contribution as an antioxidant as revealed in the RBC deformability tests. Swine enzootic pneumoniae ¡]SEP¡^, is a disease caused by Mycoplasma hyopneumoniae infection, and usually lead to considerable economic loss. Though extensive research during the past years, the molecular mechanism about the infective pathway of M. hyopneumoniae was still elusive. The membrane proteins of this microorganism were considered as critical adhesion molecules and therefore are potential candidates for vaccine development. Through immunoscreening, we had isolated five recombinant phage clones expressing 10 kDa, 32 kDa, 36 kDa, 42 kDa and 60 kDa antigen proteins from the lEMBL3 library of Mycoplasma hyopneumoniae. The clone carrying the P42 gene was subcloned and further characterized as a heat shock protein gene. In the present study, the heat-shock protein gene encoding a 42 kDa/ 65 kDa protein¡]P42/P65¡^was cloned into the mammalian expression vector pcDNA3 and obtained plasmid pcDNA42. The immune response induced by pcDNA42 was evaluated in mice. The IgG titer was obviously elevated during the first eight weeks with the IgG1 titer slightly higher than IgG2a. However, the IgM titer was not changed signifcantly. Studies on the macrophage activity and T cell cytotoxity were still undergoning.
2

Antioxidative, anti-inflammatory and antineoplastic potential of dicerocaryum species

Madiga, Maphuti Carol January 2007 (has links)
Thesis (M.Sc. (Biochemistry )) --University of Limpopo, 2007 / Refer to document / Medical Research Council (MRC), National Research Foundation (NRF) and University of Limpopo
3

Nutritivni profil, antioksidacioni potencijal i senzorski kvalitet specijalnih vrsta hlebova sa dodatkom melase šećerne repe / Nutrition profile, antioxidative potential and sensory quality of bread supplemented with sugar beet molasses

Filipčev Bojana 27 August 2009 (has links)
<p>U radu je ispitivan efekat dodatka čiste melase i voda/povrda (jabuke, &scaron;ljive, mrkva i crveni kupus), prethodno osmotski dehidriranih u melasi &scaron;ederne repe, na kvalitet hleba. Ispitivane su sledede grupe suplemenata u dve doze: čista melasa (5 i 10%, računato na bra&scaron;no), sveži (u obliku komadida osmotski dehidriranog voda/povrda, 10 i 30%, računato na bra&scaron;no) spra&scaron;eni (osu&scaron;eno i samleveno osmotski dehidrirano vode/povrde, 5 i 10%, računato na bra&scaron;no).<br />Dobijeni rezultati su pokazali da su ispitivani dodaci uticali na značajno pobolj&scaron;anje mineralnog sastava hleba. Najznačajni je povedanje u odnosu na kontrolni je zabeleženo u sadržaju kalijuma: za niže doze dodataka, najvede povedanje se kretalo u opsegu 89.1% (hleb sa melasom)-94.1% (hleb sa &scaron;ljivom u prahu) dok su za vi&scaron;e doze dodataka zabeležena slededa maksimalna povedanja:<br />157.5% (hleb sa kupusom u prahu) i 167.5% (hleb sa melasom). Hlebovi sa dodacima su takođe imali značajno vi&scaron;e sadržaje magnezijuma i kalcijuma u odnosu na kontrolni hleb. Najvi&scaron;i sadržaji Mg i Ca su određeni u hlebovima sa dodatkom vi&scaron;e doze kupusa u prahu (58 i 100%, respektivno). Hlebovi sa dodacima su pokazivali značajno vi&scaron;i antioksidacioni potencijal, pri čemu su najvi&scaron;i potencijali zabeleženi u hlebu sa dodatkom &scaron;ljive u prahu, 62.5-81.6% za 5 i 10% dodatak, respektivno.<br />Dodaci na bazi melase su uticali na promenu fizičkih, teksturnih i senzorskih svojstava hleba u pravcu smanjenja specifične zapremine, povedanja čvrstode sredine i potamnjivanja boje. Međutim, pri nižim dozama dodataka, ove promene su bile manje izražene. Hlebovi sa dodatkom jabuke i &scaron;ljive su ocenjeni kao najbolji po ukusu.</p> / <p>Osmotical dehydration in sugar beet molasses as hypertonic medium was used to treat apples, plums, carrots and red cabbage. Following the treatment, the fruits/vegetables were dried and ground. The study was aimed at determining the quality parameters of bread supplemented with the following ingredients: The freshly treated fruits/vegetables (at 10% and 30% level, flour basis), The powders derived from them (at 5% and 10% level flour basis), Sugar beet molasses (at 5% and 10% level flour basis).<br />The results showed that these ingredients significantly improved the mineral content of breads. The most marked was the increase in K content: for lower supplementation level, 89.1% (bread with<br />molasses)-94.1% (bread with plum, powder). For higher supplementation level, the rise in K content was 157.5% (bread with cabbage, powder) and 167, 5% (bread with molasses). Contents of Mg and Ca were also significantly increased as compared to the control. The highest increase in Mg and Ca was obtained by supplementation with cabbage at higher applied dose (around 58% and 100%, respectively). Moreover, the supplemented breads showed significantly higher antioxidant potentials with the highest increase measured in the breads made with plum (62.5-81.6% for 5 and 10% levels, respectively). The molasses-based ingredients influenced the physical, textural and sensory properties of bread by lowering the specific volume, increasing the crumb firmness and changing the color and flavor. However, the lower supplementation levels had relatively mild effect on these properties. The breads made with apples and plums were scored highest for flavor.</p>
4

Biološka aktivnost fermentisanih mlečnih napitaka dobijenih primenom kombuhe i konvencionalnih starter kultura / Biological activity of fermented milk beverages obtained using kombucha and conventional starter culture

Hrnjez Dajana 26 September 2015 (has links)
<p>Proizvodnja fermentisanih mliječnih napitaka unapreijeđenih funkcionalnih karakteristika postala je jedan od glavnih fokusa u industriji prerade mlijeka. Cilj doktorske disertacije je ispitivanje biolo&scaron;ke aktivnosti fermentisanih mliječnih napitaka dobijenih primjenom nekonvencionalne starter kulture, kombuhe (kultivisane na crnom čaju zaslađenim saharozom u koncentraciji od 10%) i poređenje sa karakteristikma proizvoda dobijenih primenom konvencionalnih starter kultura, jogurtne odnosno probiotske, tokom skladi&scaron;tenja. Za fermentaciju je kori&scaron;ćeno mlijeko sa 2,8% mliječne masti na temperatura 42&deg;C.<br />Promjene tokom fermentacije mlijeka primjenom kombuhe i konvencionalnih starter kultura praćene su određivanjem stepena proteolize, sadržaja laktoze, D&ndash; galaktoze, D&ndash;glukoze i D&ndash;fruktoze i masnih kiselina pri sledećim pH vrijednostima: 6,4; 6,0; 5,5; 5,0 i 4,6. Promjene antihipertenzivne aktivnosti (AKE inhibitorna aktivnost), antioksidativne aktivnosti (ABTS i DPPH metod) kao i promjene stepena proteolize, reolo&scaron;kih i senzornih karakteristika sve tri vrste fermentisanih mliječnih napitaka praćene su tokom 21-og dana skladi&scaron;tenja. Osim toga praćene su i promjene sadržaja &scaron;ećera, masnih kiselina, minerala (kalcijuma, natrijuma i kalijuma), vitamina C i biogenih amina.<br />Tokom procesa fermentacije mlijeka primjenom različitih starter kultura može se zaključiti da postoji razlika u promjenama udijela pojedinačnih proteinskih frakcija analiziranih metodom kapilarne elektroforeze.<br />Različite starter kulture utiču na različitu AKE inhibitornu aktivnost tokom skladi&scaron;tenja, &scaron;to ukazuje na različitu proteolitičku aktivnost kori&scaron;ćenih starter kultura. Utvrđeno je da AKE inhibitorna aktivnost raste tokom skladi&scaron;tenja, pri čemu uzorci proizvedeni primjenom kombuhe imaju najveću AKE inhibitornu aktivnost na kraju 14 dana skladi&scaron;tenja i ona iznosi 79,4%, dok su u jogurtu i probiotskom jogurtu te vrijednsoti 63,4 i 64,6% redom. Takođe, tokom skladi&scaron;tenja stepen proteolize raste u svim uzorcima sa značajnim međusobnim varijacijama. Antiksidativna aktivnost svih uzoraka opada tokom skladi&scaron;tenja ali je u svim uzorcima zabilježena veća aktivnost na ABTS nego na DPPH slobodne radikale. Nakon 21-og dana skladi&scaron;tenja najveći antioksidativni potencijal određen metodom stabilizacije ABTS.+ katjona imali su uzorci sa jogurtnom starter kulturom (TEAC vrijednost 8,922 mmolmg-1). U pogledu sastava masnih kiselina, tokom 14 dana skladi&scaron;tenja u kombuha fermentisanim mliječnim napicima<br />kao i napicima dobijenim sa jogurtnom i probiotskom starter kulturom dolazi do porasta udjela zasićenih (SFA) i opadanje mononezasićenih (MUFA) i polinezasićenih masnih kiselina (PUFA). Nakon 21-og dana skladi&scaron;tenja sadržaj SFA; MUFA i PUFA u kombuha fermentisanom mliječnom napitku iznosio je 65,94; 30,73 i 3,33% redom, dok su te vrijednosti kod jogurta iznosile 66,02; 30,77 i 3,21% i probiotskog jogurta 66,04; 30,66 i 3,30 % redom. Najveći sadržaj vitamina C nakon proizvodnje i 14 dana skladi&scaron;tenja imali su uzorci sa kombuha starter kulturom (0,5457 &plusmn; 0,017 mg100g-1). Uzorci dobijeni upotrebom konvencionalnih startera pokazali su bolje reolo&scaron;ke osobine pri ispitivanim uslovima tokom 21 dana skladi&scaron;tenja. Kombuha fermentisani mlečni proizvod imao je karakterističan, blago kiseli, osvežavajući ukus i nagla&scaron;enu aromu.<br />Na osnovu dobijenih rezultata biolo&scaron;ke aktivnosti i promjena kvaliteta kombuha fermentisanog mliječnog napitka tokom skladi&scaron;tenja, u odnosu na karakteristike proizvoda dobijenih upotrebom konvencionalnih starter kultura može se objasniti opravdanost upotrebe kombuha starter kulture u fermentaciji mlijeka sa ciljem dobijanja novog funkcionalnog fermentisanog mliječnog proizvoda.</p> / <p><span style="font-size:11px;">Nowadays, production of fermented dairy products with elevated benefits on human health has become one of the major focuse in dairy industry. The aim of the PhD thesis is to examine the biological activity of fermented milk products obtained using non-conventional starter culture kombucha (cultivated on black tea with 10% of sucrose) and comparision with products obtained by conventional starter cultures, probiotic/yoghurt during storage. Milk with 2.8% of milk fat was used for the samples production at temperature of 42 &deg;C.<br />The changes of components content during the milk fermentation by kombucha and conventional starter cultures were monitored at the following pH values: 6.4; 6.0; 5.5; 5.0 and 4.6., by determining the degree of proteolysis, lactose, D-galactose, D-glucose and D-fructose, fatty acids. The antihypertensive activity (ACE inhibitory activity), antioxidant activity (ABTS and DPPH tests) and the degree of proteolysis, sensory and rheological characteristics of all three types of fermented milk products were observed during 21 days of storage. Moreover, the chemical qualities of samples were monitored analyzing the contents of sugars, fatty acids, minerals (calcium, sodium and potassium), vitamin C and biogenic amines.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; There were differences in protein fractions (analyzed by capillary electrophoresis) of products obtained by using different starter cultures during the milk fermentation. Different starter cultures affect different ACE inhibitory activity during the storage, which implies different proteolytic activity of used starter cultures. It has been found that the ACE inhibitory activity was increased during the storage; wherein the samples obtained using kombucha starter culture have the highest ACE inhibitory activity at the 14th day of storage, 79,4%, while in yogurt and probiotic yoghurt it was 63.4 and 64.6% respectively. Also, the degree of proteolysis during the storage was increased in all samples with significant mutual variations. In all products, higher ABTS than 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity was determined, while both activities slightly decreased during the storage. The antioxidant activity of all samples decreases during storage. After 21 days of storage, the highest antioxidant potential, determined by the ABTS. + method had a yoghurt samples (TEAC value of 8.922 mmolmg-1). In terms of the fatty acids composition during 14 days of storage in all type of fermented dairy products relative content of SFA (saturated fatty acids - SFA) increased, while relative contents of MUFA (monounsaturated fatty acids) and PUFA (polyunsaturated fatty acids) decreased during that period of storage. After 21 days of storage the content of SFA; MUFA and PUFA in kombucha fermented milk product was 65.94; 30.73 and 3.33% respectively. In yogurt sample their content was 66.02, 30.77 and 3.21%, while in probiotic 66.04; 30.66 and 3.30% respectively. In all fermented milk products, long chain fatty acids were dominant with a total share of about 45% in all varieties of fermented dairy products. The highest content of vitamin C after production and 14 days of storage was in samples obtained by kombucha starter culture (0.5457 &plusmn; 0.017 mg100g-1). Samples obtained by conventional starter showed better overall rheological properties at the tested conditions for 21 days of storage. Kombucha fermented milk product had a characteristic, distinctive mild sour, refreshing taste and conspicuous aroma.<br />The obtained results of biological activity and the quality of kombucha fermented milk products during storage in comparison to the same characteristics of the products obtained using conventional starter culture, could explain that kombucha is convenient starter for milk fermentation with the aim of obtaining new functional fermented milk products with pronounced bioactive characteristics and distinctive sensory and rheology properties.</span></p>
5

Sinteza i fizičko-hemijska karakterizacija N-aromatičnih monosupstituisanih derivata karbohidrazona i tiokarbohidrazona / Synthesis and physicochemical haracterization of N-aromatic monosubstituted carbohydrazones аnd thiocarbohydrazones

Mrđan Gorana 25 September 2020 (has links)
<p>U ovoj doktorskoj disertaciji je radi fizičko-hemijske karakterizacije i ispitivanja potencijalne<br />biolo&scaron;ke aktivnosti sintetisano&nbsp; 40&nbsp; derivata mono(tio)karbohidrazona. Strukture dobijenih jedinjenja su potvrđene&nbsp; NMR&nbsp; i&nbsp; FT&ndash;IR&nbsp; spektroskopijom,&nbsp; elementalnom&nbsp; i&nbsp; rendgenskom&nbsp; strukturnom&nbsp; analizom. Uticaj&nbsp; rastvarača&nbsp; i&nbsp; prisutnog&nbsp; supstituenta&nbsp; na&nbsp; položaje apsorpcionih&nbsp; maksimuma&nbsp; ispitani&nbsp; su&nbsp; po principima LSER i LFER metoda. Teorijski proračuni za sintetisana jedinjenja izvedeni su&nbsp; primenom TD&ndash;DFT&nbsp; metode.&nbsp; Jonizacione&nbsp; konstante&nbsp; derivata&nbsp; mono(tio)karbohidrazona&nbsp; su&nbsp; određene potenciometrijskim&nbsp; titracijama.&nbsp; Antioksidativna&nbsp; aktivnost&nbsp; je&nbsp; određena&nbsp; primenom&nbsp; tri&nbsp; testa:&nbsp; DPPH, ABTS&nbsp; i&nbsp; FRAP&nbsp; testa.&nbsp; Antimikrobna&nbsp; aktivnost&nbsp; je&nbsp; ispitana&nbsp; mikrodilucionom&nbsp; metodom&nbsp; na&nbsp; dva&nbsp; soja bakterija:&nbsp; Staphylococcus&nbsp; aureus&nbsp; i&nbsp; Escherichia&nbsp; coli.&nbsp; Za&nbsp; jedinjenja&nbsp; koja&nbsp; su&nbsp; pokazali&nbsp; antimikrobnu aktivnost je&nbsp; ispitan procenat citotoksičnosti.&nbsp; Sveukupan&nbsp; zaključak o sličnosti i razlikama sintetisanih derivata izveden je na osnovu multivarijatnih metoda klaster analize i analize glavnih komponenti.</p> / <p>In this doctoral dissertation, 40 mono(thio)carbohydrazone derivatives were synthesized for the purpose of physico-chemical characterization and examination of potential biological activity. The structures of the obtained compounds were confirmed by NMR and FT &ndash;IR spectroscopy, elemental analysis&nbsp; and&nbsp; X-ray&nbsp; structural&nbsp; analysis.&nbsp; The&nbsp; influence&nbsp; of&nbsp; solvent&nbsp; and&nbsp; substituent&nbsp; present&nbsp; on&nbsp; the positions&nbsp; of&nbsp; absorption maxima&nbsp; was&nbsp; examined&nbsp; according&nbsp; to&nbsp; the&nbsp; principles&nbsp; of&nbsp; LSER&nbsp; and&nbsp; LFER methods.&nbsp; Theoretical&nbsp; calculations&nbsp; for&nbsp; the&nbsp; synthesized&nbsp; compounds&nbsp; were&nbsp; performed&nbsp; by&nbsp; the&nbsp; TD&ndash;DFT method.&nbsp; The&nbsp; acid&nbsp; constants&nbsp; of&nbsp; mono(thio)carbohydrazone&nbsp; derivatives&nbsp; were&nbsp; determined&nbsp; by potentiometric&nbsp; titrations.&nbsp; Antioxidant&nbsp; activity&nbsp; was&nbsp; determined&nbsp; using&nbsp; three&nbsp; tests:&nbsp; DPPH,&nbsp; ABTS&nbsp; and FRAP test. Antimicrobial activity was examined by microdilution method on two strains of bacteria: Staphylococcus&nbsp; aureus&nbsp; and&nbsp; Escherichia&nbsp; coli.&nbsp; The&nbsp; percentage&nbsp; of&nbsp; cytotoxicity&nbsp; was&nbsp; examined&nbsp; for compounds&nbsp; that&nbsp; showed&nbsp; antimicrobial&nbsp; activity.&nbsp; Overall&nbsp; conclusion&nbsp; about&nbsp; the&nbsp; similarities&nbsp; and differences of the synthesized&nbsp; derivatives was studied by multivariate&nbsp; methods of cluster analysis and analysis of principal components.</p>

Page generated in 0.2636 seconds