Дисертації з теми "Sulfated"
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Mehta, Akul. "Synthetic, Sulfated, Lignin-Based Anticoagulants." VCU Scholars Compass, 2014. http://scholarscompass.vcu.edu/etd/598.
Повний текст джерелаPereira, Amália Luz Costa. "Efeito das condições de preparação sobre as propriedades do óxido de zircônio sulfatado contendo ferro." Programa de Pós-Graduação em Química da UFBA, 2004. http://www.repositorio.ufba.br/ri/handle/ri/9949.
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Catalisadores baseados em óxidos sulfatados possuem diversas aplicações industriais, principalmente em reações que demandam sítios ácidos fortes. Visando a desenvolver métodos para obter óxidos ácidos, neste trabalho se estudou o efeito dos métodos de preparação nas propriedades dos óxidos de zircônio dopado com ferro.Os precursores foram preparados por método sol-gel a partir do nitrato de ferro e oxicloreto de zircônio à temperatura ambiente. Os sólidos secos foram impregnados com uma solução aquosa de ácido sulfúrico (0,25 e 0,5mol.L-1) e calcinados a 500 e 550°C. Foram preparadas amostras com razões molares Fe/Zr=0,2; 0,4 e 0,8, além dos óxidos puros de ferro e zircônio. Os sólidos foram caracterizados por análise química, espectroscopia no infravermelho com transformada de Fourier, difração de raios X, análise térmica (DTA e TG), medida da área superficial específica, redução termoprogramada, medidas de acidez (TPD de amônia) e espectroscopia fotoeletrônica de raios X.Observou-se a formação das fases tetragonal e monoclínica nas amostras à base de óxido de zircônio, enquanto a hematita foi encontrada nas amostras à base de óxido de ferro. Após a sulfatação dos sólidos, a fase monoclínica desapareceu enquanto a fase tetragonal foi estabilizada. Por outro lado, a hematita não foi afetada pelos íons sulfatos. A presença de ferro no óxido de zircônio também estabilizou a fase tetragonal, independente da presença de sulfato. Nas amostras com razão Fe/Zr=0,8, a hematita foi segregada, co-existindo com a fase tetragonal da zircônia. As áreas superficiais específicas dos sólidos aumentaram pela adição de ferro e foram afetadas pelos íons sulfato, mas nenhuma tendência regular foi observada em função das condições de preparação. O óxido de zircônio mostrou maior capacidade em aceitar e estabilizar íons sulfato na estrutura do que o óxido de ferro. O óxido de zircônio puro foi estável em condições redutoras na faixa de 25-1000°C, mas depois da sulfatação os sólidos perderam espécies sulfatos a 500°C. Os óxidos de ferro, entretanto sofreram redução próxima de 350°C independentemente da presença de íons sulfato. A zircônia pura foi mais ácida do que a hematita pura. A adição de ferro na zircônia não afetou significativamente o número de sítios ácidos, exceto no caso da amostra Fe/Zr(molar)=0,2 calcinada 500°C e tratada com solução 0,25mol.L-1 de ácido sulfúrico. Em geral, os sólidos mais ácidos foram produzidos usando-se estas condições. A zircônia sulfatado possui somente sítios ácidos fortes. Entretanto, a adição de ferro gerou sítios de acidez moderada e este efeito aumentou com a quantidade de ferro nos sólidos. O óxido de ferro produziu sítios de diferentes forças ácidas. A composição superficial também variou com a natureza do sólido e com o método de preparação. Os teores de ferro e enxofre foram mais baixos na superfície do que no volume. Observou-se também que o teor de ferro na superfície dos sólidos diminuiu devido à sulfatação. Entretanto, os sólidos com teores mais elevados de ferro foram capazes de reter mais enxofre na superfície. A melhor condição para se obter sólido ácidos à base de zircônio é preparar preparado pela impregnação do hidróxido de zircônio dopado com ferro (Fe/Zr=0,2), tratado com solução 0,25mol.L-1 de ácido sulfúrico seguido da calcinação a 500°C. Este material possui elevada área superficial (223m2/g), sendo promissor para aplicações catalíticas.
Salvador
Bi, Melody. "Characterization and Catalytic Properties of Sulfated Zirconia." TopSCHOLAR®, 1996. http://digitalcommons.wku.edu/theses/895.
Повний текст джерелаMehta, Shrenik. "Synthesis of a Library of Sulfated Small Molecules." VCU Scholars Compass, 2011. http://scholarscompass.vcu.edu/etd/2517.
Повний текст джерелаAbdelfadiel, Elsamani I. "INVESTIGATION OF ANTICOAGULATION PROPERTIES OF SULFATED GLYCOSAMINOGLYCAN MIMETICS." VCU Scholars Compass, 2017. http://scholarscompass.vcu.edu/etd/5054.
Повний текст джерелаMacedo, Ana AngÃlica Mathias. "Collagen - sulfated polysaccharide films with antithrombogenic properties: preparation and characterization." Universidade Federal do CearÃ, 2006. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=7709.
Повний текст джерелаFundaÃÃo de Amparo à Pesquisa do Estado do CearÃ
This work reports the preparation and characterization of collagen-sulfated polysaccharide films and applications in coating of cardiovascular prostheses. The films were prepared by adding the sulfated polysaccharide solution on soluble collagen (0, 5, 10, 20 and 25 %). The blends of collagen-sulfated polysaccharide were casted in acrylic molds, and dried at low temperature. The physico-chemical properties of collagen-sulfated polysaccharide films, were studied using infrared spectroscopy that showed absorptions typical of collagen and sulphated polysaccharide; the thermal analysis (DSC) showed that the structural integrity of collagen was unmodified during the extraction process and the polysaccharide present in the samples did not decrease the thermal stability of the collagen, which was higher for the concentrations of 20 %. In the thermal analysis (DTG), the addition of the polysaccharide caused a small decrease of the stability of thermal degradation and when was adding 5 % of the sulfated polysaccharide to the collagen, a reduction in its stability occurs, however, in the concentrations of 10, 20 and 25 %, the stability of thermal degradation of the film increased. In the impedance spectroscopy, the results are associated possibly, to the interactions between the macromolecules. The blood compatibility was analyzed by platelet adhesion and the results showed that the films possess hemocompatibility and antitrombogenic properties.
Este trabalho aborda sobre o preparo e a caracterizaÃÃo de filmes de colÃgeno-polissacarÃdeo sulfatado e sua aplicaÃÃo para revestimento de prÃteses vasculares. Os filmes foram obtidos a partir da mistura de soluÃÃo de colÃgeno e polissacarÃdeo sulfatado, nas concentraÃÃes 0, 5, 10, 20 e 25 % do polissacarÃdeo. As soluÃÃes de colÃgeno-polissacarÃdeo sulfatado foram formatadas em moldes de acrÃlico em condiÃÃes de baixa umidade e temperatura. A caracterizaÃÃo fÃsico-quÃmica dos filmes de colÃgeno-polissacarÃdeo sulfatado foi estudada por espectrometria no infravermelho que mostraram bandas tÃpicas do colÃgeno e bandas tÃpicas do polissacarÃdeo sulfatado; a anÃlise tÃrmica por DSC mostra que a integridade estrutural do colÃgeno foi preservada no processo de extraÃÃo e que a adiÃÃo do polissacarÃdeo nas amostras nÃo diminuiu a estabilidade tÃrmica do colÃgeno tendo sido maior na concentraÃÃo de 20 %. Na anÃlise tÃrmica por DTG, a adiÃÃo do polissacarÃdeo causa um pequeno decrÃscimo da estabilidade de degradaÃÃo tÃrmica e ao adicionarmos 5 % do polissacarÃdeo sulfatado ao colÃgeno, ocorre uma reduÃÃo em sua estabilidade, porÃm, a partir daÃ, nas concentraÃÃes 10, 20 e 25 %, a estabilidade de degradaÃÃo tÃrmica do filme vai aumentando. Na espectroscopia de impedÃncia, os resultados estÃo associados, possivelmente, a interaÃÃes entre as macromolÃculas. A compatibilidade sangÃÃnea foi analisada por adesÃo de plaquetas e os resultados mostraram que os filmes possuem hemocompatibilidade e propriedades antitrombogÃnicas.
Li, Xuebing. "Butane skeletal isomerization on sulfated zirconia at low temperature." [S.l. : s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=972215158.
Повний текст джерелаHenry, Brian Lawrence. "Novel Sulfated 4-Hydroxycinnamic Acid Oligomers as Potent Anticoagulants." VCU Scholars Compass, 2007. http://scholarscompass.vcu.edu/etd/1462.
Повний текст джерелаFerraro, Magda [Verfasser]. "Biodegradable Sulfated Dendritic Nanocarriers for Biomedical Applications / Magda Ferraro." Berlin : Freie Universität Berlin, 2020. http://d-nb.info/1213295025/34.
Повний текст джерелаDegirmenci, Volkan. "Methane Activation Via Bromination Over Sulfated Zirconia/sba-15 Catalysts." Phd thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/3/12609021/index.pdf.
Повний текст джерела90%) conversions dibromomethane synthesis was favored at high selectivity (~90%) under the following conditions: T=330 °
C, Br:CH4 = 3. Sulfated zirconia included SBA-15 catalysts were prepared and characterized for the catalytic methane activation via bromination. The SBA-15 sol-gel preparation technique was followed and the zirconium was added during the preparation in the form of ZrOCl2·
8H2O with 5-30 mol % ZrO2 with respect to the SiO2 content simultaneously with the silicon source (TEOS). The catalysts were sulfated in 0.25 M H2SO4 solution. The zirconium contents of the catalysts were determined by elemental analysis and 15 wt. % Zr was determined as the highest amount. XRD analysis showed the crystalline zirconia peaks only for high zirconia loadings (>
25 mol % ZrO2) indicating the good distribution of Zr in silica framework at lower loadings. BET surface areas of the sulfated catalysts are in the range of 313-246 m2/g. The porous structures of the catalysts were determined by TEM pictures, which revealed that the increase in Zr content decreased the long range order of pore structure of SBA-15 in agreement with XRD results. The acidities of the catalysts were determined by 1H MAS NMR experiments. Brø
nsted acidity was identified by a sharp 1H MAS NMR line at 10.6 ppm. The highest acidity was observed at 5.2 wt. % Zr loading according to 1H MAS NMR experiments. 29Si MAS NMR analysis showed the formation of Si-O-X linkages (X=H, Zr). Further characterization of Brø
nsted acidity was performed by FT-IR spectroscopy of adsorbed CO at 82 K. The analysis revealed that the Brø
nsted acidity of sulfated catalysts were similar to the acid strength of the conventional sulfated zirconia. In TPD experiments, the basic molecule isopropylamine (IPAm) was adsorbed and decomposition temperature of IPAm was monitored. The temperature decreased from 340 °
C to 310 °
C in sulfated catalysts, indicating the acidic character of these samples. Catalytic methane bromination reaction tests were performed in a quartz tubular reactor. The results showed that 69% methane conversion was attainable over SZr(25)SBA-15 catalyst at 340 °
C. The liquid 1H NMR measurements of the products revealed that >
99% methyl bromide selectivity was achieved.
O'Meara, Connor. "Sulfated saccharides : the force against the dark-side of histones." Phd thesis, Canberra, ACT : The Australian National University, 2016. http://hdl.handle.net/1885/155267.
Повний текст джерелаKlose, Barbara S. "Skeletal isomerization of Butane by Sulfated Zirconia Catalysts a branched field /." [S.l.] : [s.n.], 2005. http://deposit.ddb.de/cgi-bin/dokserv?idn=977894193.
Повний текст джерелаLemnitzer, Katharina, Jürgen Schiller, Jana Becher, Stephanie Möller, and Matthias Schnabelrauch. "Improvement of the Digestibility of Sulfated Hyaluronans by Bovine Testicular Hyaluronidase." Universitätsbibliothek Leipzig, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-147876.
Повний текст джерелаGiliard, Nicole Verfasser], and Robert [Akademischer Betreuer] [Schlögl. "Preparation and characterization of sulfated zirconia catalysts / Nicole Giliard. Betreuer: Robert Schlögl." Berlin : Universitätsbibliothek der Technischen Universität Berlin, 2011. http://d-nb.info/1014619653/34.
Повний текст джерелаChai, Qinyuan. "Synthesis and Characterization of Shape Memory Polyurethane/ureas Containing Sulfated Sugar Units." University of Cincinnati / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1521192318273219.
Повний текст джерелаVerghese, Jenson. "SYNTHESIS AND BIOCHEMICAL STUDIES ON SULFATED MONOMERS OF LOW MOLECULAR WEIGHT LIGNINS." VCU Scholars Compass, 2009. http://scholarscompass.vcu.edu/etd/1868.
Повний текст джерелаTruong, Tien M. "SULFATED DEHYDROPOLYMER OF CAFFEIC ACID FOR REPAIR OF LUNG DAMAGE AND EMPHYSEMA." VCU Scholars Compass, 2016. http://scholarscompass.vcu.edu/etd/4229.
Повний текст джерелаPEREIRA, Carlos Eduardo. "Incorporação da zircônia sulfatada a peneira molecular MCM-41 para ser utilizada na reação de transesterificação." Universidade Federal de Campina Grande, 2017. http://dspace.sti.ufcg.edu.br:8080/jspui/handle/riufcg/1481.
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A peneira molecular MCM-41 é considerada promissora como suporte para os óxidos metálicos em processo de refino de petróleo, adsorventes e catalisadores. Os catalisadores heterogêneos apresentam grande potencial de viabilizar a produção de biodiesel através da reação de transesterificação. A síntese da peneira molecular MCM-41 foi realizada a partir da água deionizada, brometo de cetiltrimetilamônio, hidróxido de amônio, etanol e ortossilicato de tetraetila. O óxido de zircônia foi obtido pelo método sol-gel a partir do oxicloreto de zircônio com hidróxido de amônio à temperatura ambiente e ativado por calcinação a 550 e 700°C. Em seguida o óxido de zircônia ativado foi sulfatado, seco e calcinado a 400 °C. A zircônia sulfatada foi incorporada a peneira molecular MCM-41 por impregnação via úmida, com diferentes proporções mássicas (10, 20, 30, 40, 50%). Verifica-se que a partir das análises de difração de raio X a formação da peneira molecular MCM-41 confirmou a estrutura hexagonal e a fase mesoporosa. Observou-se formação das fases, tetragonal e monoclínica do óxido de zircônia. Através da espectroscopia de absorção na região do infravermelho com transformada de Fourier foi possível detectar picos referentes a presença de íons sulfatos bidentados ligado a superfície da zircônia. As propriedades texturais apresentaram estruturas com poros bimodais após o processo de incorporação da zircônia sulfatada. As micrografias do óxido de zircônia ativadas a 550 e 700 °C apresentaram tricas em sua superfície antes e após de incorporação da zircônia sulfatada. O potencial catalítico foi avaliado na reação transesterificação do óleo de soja por rota metílica. O catalisador com óxido de zircônia ativado a 700 °C e sulfatado e incorporado a peneira molecular com 40% (em peso) apresentou maior conversão de ésteres metílicos 83,8%. No entanto, esta conversão não especifica o óleo obtido como biodiesel de acordo com a norma da Agência Nacional de Petróleo, Gás Natural e Combustíveis. Assim como o índice de acidez. Porém os resultados de densidade e viscosidade estão de acordo com a especificação estabelecida pelas normas.
The MCM-41 molecular sieve is considered promising as a support for the petroleum refining metal oxides, adsorbents and catalysts. Heterogeneous catalysts have great potential to make viable the production of biodiesel through the transesterification reaction. The synthesis of the MCM-41 molecular sieve was performed from deionized water, cetyltrimethylammonium bromide (CTABr), ammonium hydroxide (NH4OH), ethanol and tetraethyl orthosilicate (TEOS). The zirconium oxide was obtained by the sol-gel method from zirconium oxychloride with ammonium hydroxide at room temperature, the material was activated at 550 and 700 °C, and thereafter, sulphated. The material was then activated using the calcination process at 550 and 700 ° C and sulfated. The sulfation process was carried out with a 0.5 mol.L-1 sulfuric acid solution and allowed to stand for 30 minutes, dried for 12 h at 120 ° C and calcined at 400 ° C. The process of incorporation of ZS into the MCM-41 molecular sieve was done using different mass proportions (10, 20, 30, 40 and 50%) in relation to the mass of the MCM-41 molecular sieve, by wet method. It was verified from the analyzes of X-ray diffraction, the adsorption of nitrogen (BET method) and Fourier transform infrared spectroscopy (FTIR) the crystalline and textural properties which confirmed the molecular sieve obtainment and the presence of the tetragonal and monoclinic phases of the sulfated zirconia in the mesoporous structure. The micrographs of activated zirconium oxide at 550 and 700 °C and sulphated showed dispersed particles with the presence of cracks on its surface, after the incorporation there were no modifications in the structure. The catalytic activity was evaluated by the transesterification reaction of the soybean oil via the methyl route, using all the catalysts which were synthesized. The results showed that the catalyst 50_ZS/MCM-41_550 °C showed a greater conversion of methyl esters of 81.4% with the predominant tetragonal phase. The catalyst with the zirconium oxide activated at 700 °C obtained a conversion of 83.8% to the 40_ZS/MCM-41_700 °C catalyst, with the predominant monoclinic phase. However, the ester content of the oil samples was below the value established by the National Agency of Petroleum, Natural Gas and Fuels (ANP). The density and kinematic viscosity of the catalysts under study X_ZS/MCM-41 were in the range of the established standard. The acidity index was above the specified values, confirmed by the high percentage of free fatty acids in the oil.
Fenner, Amanda Marie. "Design, synthesis, and evaluation of small molecule glycosaminoglycan mimics." Diss., University of Iowa, 2011. https://ir.uiowa.edu/etd/4984.
Повний текст джерелаIgdoura, Suleiman Abdalla. "Biogenesis, sorting and trafficking of sulfated glycoprotein-1 (SGP-1) in rat Sertoli cells." Thesis, McGill University, 1994. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=28467.
Повний текст джерелаSGP-1 exists in two forms, a 65 kDa and a 70 kDa form. Labeling experiments demonstrated that the 65 kDa form of SGP-1 is synthesized first then post-translationally modified to the 70 kDa form. Western blot analysis of purified Sertoli cell lysosomes revealed a 65 kDa protein and 15 kDa proteins. The latter were isolated and shown to be saposins which were possibly derived from the 65 kDa precursor. Immunocytochemical studies using anti SGP-1 antibodies demonstrated that lysosomes deliver SGP-1 or/and saposins to phagosomes containing residual bodies. Thus, besides a secretory route of SGP-1 there appears to be a lysosomal pathway that may play a significant role in the hydrolysis of glycolipids of spermatid membranes present in phagocytosed residual bodies. Permeabilization of purified Sertoli Golgi fractions revealed that the 65 kDa protein is strongly associated with Golgi membrane. This association was resistant to low pH, resistant to excess free mannose 6-phosphate and independent of N-linked glycosylation, but sensitive to EDTA treatment. In contrast, the 70 kDa form of SGP-1 was released from permeabilized Golgi Fractions at pH 7.4 and 5.4 but retained at pH 6.4 indicating that it is a soluble protein with biochemical characteristics of a regulated secretory protein. In vivo treatment with tunicamycin resulted in an increase in the density of lysosomal SGP-1 suggesting that N-linked carbohydrate residues are not essential for the targeting of this protein to the lysosomes of Sertoli cells. In contrast, in the nonciliated cells of the efferent duct, tunicamycin treatment resulted in a significant reduction in the labeling density of lysosomal SGP-1 suggesting a sugar dependent lysosomal transport mechanism.
Thus, this study demonstrates a unique lysosomal form of SGP-1 (65 kDa). The targeting of the 65 kDa form to the lysosomes and eventually to the phagosomes involves an early association with Golgi membranes independent of mannose 6-phosphate receptors. The trafficking of the 70 kDa form of SGP-1 to the tubular lumen may depend on its selective segregation into secretion granules within the Golgi apparatus of Sertoli cells. Finally, the expression of SGP-1 by Sertoli cells is modulated by androgens.
Kumari, Shalini [Verfasser]. "Sulfated Multivalent Polymers for inhibition of L-selectin and LOX-1 Receptors / Shalini Kumari." Berlin : Freie Universität Berlin, 2019. http://d-nb.info/1178424499/34.
Повний текст джерелаHintze, Vera, Sergey Samsonov, Sandra Rother, Sarah Vogel, Sebastian Köhling, Stephanie Moeller, Matthias Schnabelrauch та ін. "Sulfated Hyaluronan Derivatives Modulate TGF-β1:Receptor Complex Formation: Possible Consequences for TGF-β1 Signaling". Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-230329.
Повний текст джерелаBarin, Katayoun Katy. "Postnatal developmental study and expression of immobilin and sulfated glycoprotein-2 in the rat epididymis." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape16/PQDD_0003/MQ29649.pdf.
Повний текст джерелаYan, Jinglan. "Sulfated ß-cyclodextrins in enantiomeric separations and mobility conservation model in cyclodextrin-mediated capillary electrophoresis." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ35009.pdf.
Повний текст джерелаMcIntosh, Debra Joy. "Synthesis and characterization of mesoporous sulfated zirconia and its use as a solid acid catalyst." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape7/PQDD_0019/MQ48026.pdf.
Повний текст джерелаWarren, Stacey. "A critical analysis of the 1,9-dimethylmethylene blue assay for sulfated glycosaminoglycans in synovial fluid." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0017/MQ55725.pdf.
Повний текст джерелаBarin, Katayoun. "Postnatal developmental study and expression of immobilin and sulfated glycoprotein-2 in the rat epididymis." Thesis, McGill University, 1996. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=27275.
Повний текст джерелаChan-Thaw, Carine. "Sulfated zirconia deactivation during n-butane isomerization : An in situ UV-vis-NIR spectroscopic study." Université Louis Pasteur (Strasbourg) (1971-2008), 2008. https://publication-theses.unistra.fr/public/theses_doctorat/2008/CHAN-THAW_Carine_2008.pdf.
Повний текст джерелаThe deactivation phenomena during n-butane isomerization on sulfated zirconia (SZ) and manganese-promoted sulfated zirconia (MnSZ, 0. 5 or 2 wt% Mn) are investigated at 323 or 373 K by in situ UV-vis-NIR diffuse reflectance spectroscopy and on-line gas chromatography. Sulfated zirconia (SZ) catalysts are found to deactivate in two steps at 373 K: a fast initial and a slow second phase. The well accepted mechanism for the initiation step of the isomerization is the oxidative dehydrogenation (ODH). SZ is an acid catalyst with very few active sites. The access to these sites can be blocked when some species are adsorbed on them. This work confirms the duality effect of the products of ODH: water and butene - their positive and negative effects on n-butane isomerization. An appropriate hydration level of SZ is important for the activity of the catalyst. Thus, the activation conditions (atmosphere and temperature) play a major role. However, excess water on the catalyst surface (band at 1910 nm in the NIR range) can block the access of the reactant to the active sites and thus diminishes the catalyst activity. In this work, it is shown that the water formed during the first few hours on stream is responsible for the first deactivation step. As it has been reported in the literature, butene is another product of ODH and after its protonation by the Brønsted acid sites; sec-butyl carbenium ions stabilized by alkoxy groups are formed. The skeletal rearrangement can proceed through a bimolecular mechanism via an alkylation of the secondary butyl carbenium ion with another olefin. However, the presence of olefin in high quantities can be another reason for the deactivation of the catalyst. The addition of propene to the feed leads to the formation of oligomers. A similar effect on the deactivation of the catalyst is observed when oxygen is present in the system. The addition of oxygen to the feed leads to the combustion of carbonaceous deposits with the formation of water, carbon dioxide and heat. Moreover the heat can favour the formation of polymers. Oligomers were detected on the catalyst surface, with their absorption bands at 370 nm and 450 nm. The experiments showed that their formation corresponds to the second phase in SZ activity decline. These species are good candidates to explain the second step of SZ deactivation. Our study demonstrates that the monoenic allylic species (absorbing at 295 nm) detected on the catalyst during reaction, are only spectators, and not responsible for the deactivation phenomena, as reported in the literature. These species were not detected in the UV-vis spectra of MnSZ in spite of its severe deactivation. However, two bands were observed in the visible range of MnSZ spectra. An erroneous assignment of these bands in the literature could be corrected with the help of calculations. The absorption band at 580 nm arises from Mn4+ and the one at 680 nm from Mn3+
Katalysatoren auf der Basis von sulfatiertem Zirkondioxid (SZ) desaktivieren, während der Isomeriesierung von kurzkettigen Alkanen, sehr schnell. Dieser schnellen Desaktivierung zu Reaktionsbeginn folgt eine zweite Phase mit verlangsamter Desaktivierung. Das Desaktivierungverhalten während der n-Butan-Isomerisierung über sulfatiertem Zirkonoxid (SZ) und mangandotiertem sulfatierten Zirkonoxid (MnSZ; 0,5 or 2,0 wt% Mn) wurden mit Hilfe der in situ UV-vis-NIR-Spektroskopie in diffuser Reflexion, d. H. Simultane Analyse des Reaktiongases durch gaschromatographische Verfahren, untersucht. Der derzeit akzeptierte Mechanismus für den Reaktionsstart ist eine oxidative Dehydrogenierung (ODH). SZ ist ein saurer Katalysator mit wenigen aktiven Oberflächenzentren, welche leicht durch Adsorption von Edukten/Reaktionsprodukten blockiert werden können. Diese Arbeit zeigt die Dualität des Einflusses von Wasser und Buten, der Reaktionsprodukte der ODH, ihren positiven und negativen Effekt auf die n- Butan-Isomerisierung. Ein optimaler Hydratisierungsgrad des SZ ist entscheidend für die Aktivität des Katalysators. Der Hydratisierungsgrad wird maßgeblich durch die Aktivierungsbedingungen (Gaszusammensetzung und Temperatur) bestimmt. Bei nicht Einhaltung des optimalen Hydratisierungsgrades kann Wasser (Absorptionband bei 1910 nm) die aktiven Zentren blockieren und somit die Aktivität des Katalysators herabsetzen. In der vorliegenden Arbeit kann gezeigt werden, dass die Bildung von Wasser in den ersten Stunden der Reaktion für die schnelle Desaktivierung zu Reaktionsbeginn verantwortlich ist. Wie in der Literatur bereits beschrieben ist, wird Buten durch Protonierung an sauren Brønsted-Zentren, über Carbenium-Intermediate, in das entsprechende Alkoxid überführt. Die Skelettisomerisierung von n-Butan folgt einem bimolekularen Mechanismus und verläuft über die Alkylierung von Gasphasenolefinen mit sec-Butyl-Carbeniumionen. Die Gegenwart von größeren Mengen an Olefinen ist jedoch ein weiterer Grund für die Katalysatordeaktivierung. Die Zugabe von Propen zum Reaktionsgemisch führte zur Bildung von Polymeren. Die Zugabe von Sauerstoff zum Reaktionsgemisch führt zur Verbrennung von kohlenstoffhaltigen Ablagerungen auf der Katalysatoroberfläche und zur Bildung von Wasser, Kohlendioxid sowie Wärme, was vergleichbare Desaktivierungserscheinungen hervorruft. Die Freisetzung von Wärme fördert zusätzlich die Bildung von Polymeren. Oligomere konnten durch ihre Absorptionsbanden bei 370 und 450 nm auf der Katalysatoroberfläche nachgewiesen werden. Die vorliegende Arbeit zeigt, dass die Bildung oligomerer Spezies eine mögliche Ursache für den zweiten, langsameren Desaktivierungsvorgang ist. Die während der Reaktion gebildete monomere Allyl-Spezies (Absorption bei 295 nm) ist entgegen der Literatur nicht für die Desaktivierungsphänomene verantwortlich. Keine der auf SZ gefundenen allylischen Spezies konnte auf MnSZ nachgewiesen werden. Jedoch desaktiviert MnSZ sehr schnell. Zwei Banden im UV-vis Bereich von Spektren der MnSZ-Katalysatoren werden beobachtet. Die fehlerhafte Zuordnung dieser Banden in der Literatur konnte durch Simulation der Spektren korrigiert werden. Die Absorption bei 580 nm ist auf Mn4+, die bei 680 nm auf Mn3+ zurückzuführen
Labidi, Sana. "Elaboration des nanoparticules d'oxyde de zirconium par voie sol-gel : mise en forme et application pour la synthèse de biodiesel." Thesis, Sorbonne Paris Cité, 2015. http://www.theses.fr/2015USPCD085/document.
Повний текст джерелаIn this work, we have realized novel nanoparticulate catalysts ZrO₂-SO₄²⁻ for biofuel production. We have studied nucleation-growth kinetics of zirconium-oxo-alkoxy (ZOA) nanoparticles in the sol-gel process. The monodispersed nanoparticles of 3.6 nm diameter were realised in a sol-gel reactor with rapid (turbulent) micro-mixing of liquid solutions containing ZNP and H₂O in 1-propanol at 20°C. The nanocoatings were realised of stable colloids of ZOA nanoparticles on silica beads along with common powders obtained after precipitation of unstable colloids. The acid ZrO₂-SO₄²⁻" catalysts were prepared after drying at 80°C, wet impregnation in 0.25 mol.L⁻¹ aqueous solution of sulfuric acid and subsequent thermal treatment between 500 and 700°C and studied with BET, DTA-DSC, TEM, DRIFT, elemental analysis, DRX and other methods. The catalyst nanocoatings calcinated at 580°C showed strong activity in esterification reaction of palmitic acid in methanol at 65°C, which is about 50 times higher than that of nanopowders, and also possesses the highest stability towards recycling. Tha catalytic performance of catalytic nanocoatings was also confirmed on unedible and waste oils
Lins, KÃzia Oliveira Abrantes de Lacerda. "Estudo das atividades antitumoral e imunoestimulante do polissacarÃdeo sulfatado isolado de Champia feldmannii Diaz-Pifferer (1977)." Universidade Federal do CearÃ, 2008. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=1832.
Повний текст джерелаO cÃncer à uma doenÃa que afeta cada vez mais um nÃmero maior de pessoas em todo o mundo. As terapias atuais utilizadas para o tratamento do cÃncer sÃo ainda insatisfatÃrias. Produtos naturais tÃm sido avaliados para seleÃÃo de compostos ativos, capazes de reduzir os tumores malignos de uma forma mais eficiente e com menos efeitos indesejÃveis. O polissacarÃdeo sulfatado extraÃdo da alga Champia feldmannii (Cf-PLS) foi testado para avaliaÃÃo do seu potencial antitumoral e imunoestimulante. AlÃm disso, foram feitos testes de toxicidade do fÃgado, rins e baÃo apÃs o tratamento com Cf-PLS. Os resultados demonstraram que Cf-PLS nÃo apresenta citotoxicidade in vitro, mas à capaz de reduzir o tumor Sarcoma 180 implantado em camundongos em 48,16% e 48,62% nas doses de 10 e 25mg/kg, respectivamente, e reduz 68,32% quando adiministrado juntamente com 5-Fluorouracil (5-FU). As anÃlises do fÃgado e rins revelaram que houve certa toxicidade no rim, com Ãreas de necrose tubular aguda na maior dose. Os testes da perfusÃo renal revelaram que Cf-PLS causa aumento da pressÃo de perfusÃo, resistÃncia vascular renal, ritmo de filtraÃÃo glomerular e fluxo urinÃrio, alÃm da excreÃÃo de sÃdio, cloreto e potÃssio. NÃo houve alteraÃÃes nos percentuais de transporte totais ou tubular proximais de sÃdio, cloreto ou potÃssio. Houve discreta deposiÃÃo protÃica nos glomÃrulos e tÃbulos renais. NÃo houve alteraÃÃes nas anÃlises bioquÃmicas e os testes hematolÃgicos revelaram uma leucopenia causada por 5-FU, entretanto esta foi revertida pelo tratamento com Cf-PLS. TambÃm foi demonstrado que Cf-PLS age como agente imunoestimulante e imunomodulador, aumentando a produÃÃo de anticorpos totais e especÃficos contra Cf-PLS e OVA, aumentando tambÃm a polpa branca e o nÃmero de megacariÃcitos nos baÃos dos animais tratados e induzindo a migraÃÃo de neutrÃfilos para a cavidade peritoneal de camundongos. Pode-se concluir que Cf-PLS apresenta atividade antitumoral e que isso pode estar relacionado com suas propriedades imunoestimulantes.
Cancer is a desease that occurs in a larger number of people each year. The therapies used to treat it are still not satisfatory. Natural products have been studied to select new compounds capable of reducing tumours and with fewer side effects. The sulfated polysaccharide isolated from the seaweed C. feldmannii (Cf-PLS) was investigated for its antitumor and immunostimulating properties and also for the toxicological aspects related to Cf-PLS treatment. The Cf-PLS did not show any significant in vitro cytotoxic effect, but showed a strong in vivo antitumor effect. The inhibition rates of sarcoma 180 tumor development were 48.16 % and 48.62% at the doses of 10 and 25 mg/kg, respectively, and 68.32% when treated together with 5-fluorouracil (5-FU). The histopathological analysis of liver and kidney showed that the kidneys were affected by Cf-PLS-treatment, presenting some focal areas of acute tubular necrosis at the higher dose. Cf-PLS caused considerable changes in renal physiology, as shown by an increase in parameters such as perfusion pressure, renal vascular resistance, glomerular filtration rate, urinary flow and sodium, chloride and potassium excretion. Neither enzymatic activity of alanine aminotransferase, urea nor creatinin levels were significantly altered. In hematological analyses, leucopeny was observed after 5-FU treatment, but this effect was prevented when the treatment was associated with the Cf-PLS. It was also demonstrated that Cf-PLS acts as an immunomodulatory agent, raising the production of specific antibodies, and also increasing the production of OVA-specific antibodies. In addition, it induced a discreet increase of the white pulp and nest of megakaryocytic in spleen of treated mice and the neutrophil migration to the intraperitoneal cavity of mice. In conclusion, Cf-PLS has some interesting antitumour activity that could be associated with its immunostimulanting properties.
Liu, Meimei. "Development of Sol-Gel Prepared Palladium-Based Sulfated Zirconia Catalysts for Nitrogen Oxides Reduction with Methane." The Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=osu1253296767.
Повний текст джерелаVogel, Sarah, Simon Arnoldini, Stephanie Möller, Ute Hempel, and Matthias Schnabelrauch. "Sulfated hyaluronan alters fibronectin matrix assembly and promotes osteogenic differentiation of human bone marrow stromal cells." Nature Publishing Group, 2016. https://tud.qucosa.de/id/qucosa%3A29174.
Повний текст джерелаVogel, Sarah, Simon Arnoldini, Stephanie Möller, Ute Hempel, and Matthias Schnabelrauch. "Sulfated hyaluronan alters fibronectin matrix assembly and promotes osteogenic differentiation of human bone marrow stromal cells." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-221028.
Повний текст джерелаPieler, Michael Martin [Verfasser]. "Investigation of influenza virus particle aggregation and purification with magnetic sulfated cellulose particles / Michael Martin Pieler." Magdeburg : Universitätsbibliothek, 2017. http://d-nb.info/1136955127/34.
Повний текст джерелаAbdel, Aziz May. "Kinetic and Thermodynamic Studies of Thrombin Inhibitors." VCU Scholars Compass, 2013. http://scholarscompass.vcu.edu/etd/2956.
Повний текст джерелаBusby, Michael Brent. "Two new, single-isomer, sulfated β-cyclodextrins for use as chiral resolving agents for enantiomer separations in capillary electrophoresis." Texas A&M University, 2005. http://hdl.handle.net/1969.1/3737.
Повний текст джерелаSingabraya, Dominique. "L’impression moléculaire pour la reconnaissance spécifique des glycannes sulfatés d’intérêt biologique." Thesis, Paris Est, 2010. http://www.theses.fr/2010PEST0049.
Повний текст джерелаGlycosaminoglycans (GAGs) are polysulfated polysaccharide molecules involved in many biological processes such as cellular proliferation, differentiation or migration, blood clotting or viral infection. It is generally admitted that a particular GAG sequence is connected to a specific biological function. Depending on their composition in disaccharides, GAGs are classified into subfamilies whose overall chemical structures are known. Unlike gene or protein sequencing, determination of the exact saccharidic sequence involved in a particular biological function is not yet possible with the available technological tools. "Glycomics" is a real challenge nowadays. One of the most innovative technologies to achieve this goal seems to be the molecular imprinting. Indeed, it provides polymers (MIPs for Molecular Imprinted Polymer) imprinted by the structural form of a target molecule.Based on previous studies performed with simple sulfated saccharides, this technology has been applied to the recognition of complex sulfated glycans. MIPs were achieved demonstrating specific and selective recognition for a Low Molecular Weight Heparin or a synthetic anticoagulant mimetic. Other MIPs were able to temporally immobilize sugars which make them available for stereo-specific modifications. Screening of optimal synthesis conditions of MIPs appeared a necessary step to obtain a specific and selective recognition. These studies open further possibilities to analyze GAG sequences carrying biological functions by the molecular imprinting technology
Wener, Kenneth Michael. "The distribution of sulfated glycoprotein-2 (SGP-2) in the hypothalamus of normal and estradiol-lesioned rats." Thesis, McGill University, 1995. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=23434.
Повний текст джерелаMosher, Stephen [Verfasser], and Thorsten [Akademischer Betreuer] Nürnberger. "The tyrosine-sulfated peptide receptors PSKR1 and PSY1R modulate Arabidopsis immune responses / Stephen Mosher ; Betreuer: Thorsten Nürnberger." Tübingen : Universitätsbibliothek Tübingen, 2013. http://d-nb.info/1163235083/34.
Повний текст джерелаCarneiro, Josà Gerardo. "Efeitos dos polissacarÃdeos sulfatados da alga marinha verde Caulerpa mexicana Sonder ex KÃtzing na nocicepÃÃo e inflamaÃÃo." Universidade Federal do CearÃ, 2012. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=8350.
Повний текст джерелаPolissacarÃdeos sulfatados de algas marinhas sÃo polÃmeros heterogÃneos que representam biomolÃculas de interesse comercial, principalmente nas indÃstrias alimentÃcia e farmacÃutica. O presente trabalho teve como finalidade avaliar os efeitos dos polissacarÃdeos sulfatados totais (PST) da alga marinha verde Caulerpa mexicana em modelos clÃssicos de nocicepÃÃo e inflamaÃÃo aguda em animais. Foram utilizados camundongos Swiss machos (18-25 g) e ratos Wistar machos (120-260 g). O rendimento de PST obtidos da extraÃÃo por digestÃo enzimÃtica foi de 1,7%. Na anÃlise por espectroscopia na regiÃo do infravermelho foram caracterizados como polissacarÃdeos contendo, principalmente, galactose sulfatada e Ãcido urÃnico. Os PST da alga C. mexicana foram capazes de reduzir (p<0,05) o nÃmero de contorÃÃes abdominais induzidas por Ãcido acÃtico (1%) em 31,8; 74,5 e 88,9% nas doses de 5, 10 e 20 (mg/kg; i.v.), respectivamente. No teste da formalina, os PST inibiram (p<0,05) o tempo de lambedura da pata somente na segunda fase do teste (88,6 e 98,5% para as doses 10 e 20 mg/kg; i.v., respectivamente). No teste da placa quente, os PST nÃo demonstraram efeito antinociceptivo no decorrer dos 90 minutos do teste. Desta forma, os resultados sugerem que os PST exerceram um efeito antinociceptivo de aÃÃo perifÃrica. Em adiÃÃo, os PST (5, 10 e 20 mg/kg) apresentaram efeito anti-inflamatÃrio quando administrados por via s.c. em ratos Wistar no modelo de edema de pata induzido por carragenana, dextrana e histamina. Para analisar o envolvimento da via heme oxigenase (HO) no efeito anti-inflamatÃrio dos PST (20 mg/kg; s.c.), os animais foram prÃ-tratados por via s.c. com um inibidor de HO especÃfico (zinco protopofirina IX). Os resultados obtidos demonstraram que os PST foram capazes de reduzir o edema de pata induzido por carragenana na terceira hora, cujo resultado foi comprovado pela quantificaÃÃo da mieloperoxidase. AlÃm disso, os PST reduziram o edema induzido por dextrana ou histamina em modelos de edema de pata nos primeiros 30 minutos apÃs a aplicaÃÃo dos agentes flogÃsticos. O efeito anti-inflamatÃrio dos PST no edema de pata induzido por carragenana nÃo foi observado apÃs inibiÃÃo prÃvia por zinco protopofirina IX. Portanto, sugerimos que o efeito anti-inflamatÃrio dos PST da alga C. mexicana pode estar relacionado com a inibiÃÃo da liberaÃÃo de histamina, reduÃÃo da migraÃÃo celular e ativaÃÃo da via da HO. Para avaliar os efeitos sistÃmicos dos PST, estes foram administrados por via i.v. (20 mg/kg) em camundongos em dose Ãnica e as alteraÃÃes sistÃmicas avaliadas durante 48 h. Os resultados obtidos demonstraram que os PST nÃo causaram mortalidade e nem alteraÃÃes macroscÃpicas significativas dos ÃrgÃos e dos parÃmetros bioquÃmicos avaliados, sendo, portanto, considerados seguros na dose testada. Em resumo, os PST da alga C. mexicana apresentaram efeitos antinociceptivos e anti-inflamatÃrios significativos, tornando-se uma importante ferramenta biotecnolÃgica para estudos posteriores.
Sulfated polysaccharides from seaweed are heterogeneous polymers representing biomolecules of commercial interest, especially in food and pharmaceutical industries. The aim this study was to evaluate the effects of total sulfated polysaccharides (TSP) of the green seaweed Caulerpa mexicana in classical models of nociception and acute inflammation in animals. Swiss male mice (18-25 g) and male Wistar rats (120-260 g) were used. The yield of the extraction of TSP obtained by enzymatic digestion was 1.7%. In analysis by Fourier transformed infrared were characterized as polysaccharides containing mainly sulfated galactose and uronic acid. The TSP of the alga C. mexicana were able to decrease (p <0.05) the number of writhes induced by acetic acid (1%) on 31.8, 74.5 and 88.9% at doses of 5, 10 and 20 mg/kg; i.v., respectively. In the formalin test, the TSP inhibited (p <0.05) the licking time of the paw only on the second of the test phase (88.6 and 98.5% for the doses 10 and 20 mg/kg; i.v., respectively). In the hot plate test, the TSP did not show antinociceptive effect in the course of 90 minutes of the test. Thus, the results suggest that the TSP presented analgesic effect by a peripheral action. In addition, TSP (5, 10 and 20 mg/kg) showed anti-inflammatory effect when administered s.c. in rats on paw edema models induced by carrageenan, dextran or histamine. To analyze the involvement of heme oxygenase (HO) pathway in the anti-inflammatory effect of TSP (20 mg/kg, sc), the animals were pretreated (s.c.) with a specific HO inhibitor (zinc protoporphirin IX). The results showed that the TSP were able to reduce the paw edema induced by carrageenan in the third hour, which was confirmed by myeloperoxidase quantification. In addition, the TSP reduced the edema induced by dextran or histamine in paw edema models in the first thirty minutes after application the flogistic agents. The anti-inflammatory effect of TSP on paw edema induced by carrageenan was not observed after prior inhibition by zinc protoporphyrin IX. Therefore, we suggest that the anti-inflammatory effect of TSP of the alga C. mexicana algae may be related to inhibition of the histamine release, reduction of cell migration and activation of the HO pathway. To evaluate the systemic effects of TSP, they were administered (i.v.) in mice (20 mg/kg) in a single-dose and evaluated the systemic changes for 48 h. The results showed that the TSP did not cause mortality or significant alterations on organs and on biochemical parameters being considered safe in the tested dose. In summary, the TSP from the algae C. mexicana have showed significant antinociceptive and anti-inflammatory effects, becoming an important biotechnological tool for further studies.
Hay, Nina. "Alternative splicing and tissue distribution of the mouse sulfated glycoprotein-1 (SGP-1prosaposin) mRNA and its translation product." Thesis, McGill University, 1996. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=27338.
Повний текст джерелаChance, Deborah L. "Sulfated sugars in cystic fibrosis mucins and the effects of sugar sulfation on the growth of Pseudomonas aeruginosa /." free to MU campus, to others for purchase, 1997. http://wwwlib.umi.com/cr/mo/fullcit?p9841269.
Повний текст джерелаFernández, Palacios Eva. "Integrated assessment of long-term sulfidogenesis in UASB reactors using crude glycerol as carbon source." Doctoral thesis, Universitat Autònoma de Barcelona, 2020. http://hdl.handle.net/10803/670499.
Повний текст джерелаMuchas actividades industriales generan emisiones que contienen compuestos de azufre tanto en efluentes líquidos como emisiones gaseosas, que mayoritariamente son tratadas mediante procesos fisicoquímicos. El sulfato se encuentra generalmente en las aguas residuales de estas industrias, como la industria papelera, la farmacéutica, la minera o la alimentaria. Como tal, el sulfato no es un compuesto nocivo, pero si se vierte en los ríos o en los sistemas de alcantarillado, puede generarse un desequilibrio en el ciclo del azufre. Dentro de este ciclo, el producto final de la reducción de compuestos dentro del mismo es el sulfuro de hidrógeno (H2S). Este compuesto es corrosivo, oloroso y se ha demostrado que es tóxico en bajas concentraciones. Por estos motivos, es necesario desarrollar alternativas respetuosas con el medio ambiente para tratar y valorizar no sólo las emisiones de SO2 sino también los efluentes líquidos ricos en azufre. Además, podría recuperarse azufre elemental de esos efluentes, lo que brindaría la oportunidad de recuperar recursos en el marco de la economía circular. Con estas premisas, el proyecto SONOVA, en el cual se enmarca esta tesis, desarrolló un proceso integral de tratamiento del SOx y el NOx proveniente de gases de combustión mediante procesos biológicos, económicos, robustos y respetuosos con el medio ambiente que también tienen en cuenta la reutilización de energía y recursos a lo largo del proceso, así como la valorización de residuos. El proceso propuesto se basa en una primera doble etapa para la absorción selectiva de SOx y NOx; una segunda etapa biológica para reducir el sulfato de la primera etapa de absorción a sulfuro de hidrógeno (que es el objetivo de estudio de esta tesis); y una tercera etapa biológica para la oxidación del sulfuro de hidrógeno a azufre elemental y su posterior recuperación. El desarrollado de sistemas, como el reactor de lecho de lodo anaerobio de flujo ascendente (UASB), han sido implementados para el tratamiento de diversas aguas residuales y para la digestión anaerobia. En esta tesis, se estudió el uso de este tipo de reactor UASB para el tratamiento de aguas sintéticas con sulfato, específicamente, se seleccionó el glicerol crudo como fuente de carbono y donador de electrones. Se utilizaron tanto procesos fisicoquímicos como técnicas de biología molecular para obtener un mayor conocimiento del proceso. Se estudió la influencia de posibles inhibiciones y la competencia entre las bacterias sulfato reductoras y los metanógenos a fin de mejorar la eliminación de sulfato y la producción de sulfuro. Se observó que en las operaciones a largo plazo (después de 200 días aproximadamente) los metanógenos desaparecen del sistema y las bacterias sulfato reductoras son las que lo colonizan. Sin embargo, se observó una acumulación de acetato como consecuencia de la desaparición de los metanógenos, lo que dio lugar a una pérdida de la fuente de carbono en la salida del reactor que podría haberse utilizado para producir sulfuro. Las operaciones a largo plazo permiten detectar otras limitaciones del sistema. A lo largo de las operaciones del UASB llevadas a cabo en esta tesis, se observó una pérdida de la estructura granular y el crecimiento de una biopelícula no metanogénica ni sulfatoreductora no identificada. Esta biopelícula, llamada slime a lo largo de esta tesis, se consideró como un factor crucial que afectaba a nuestro sistema, confiriendo propiedades como la viscosidad al lodo granular. En consecuencia, se pudieron observar problemas relacionados con la limitación de transferencia de materia, que afectaba también a la actividad sulfato reductora de los gránulos y que condujo a operaciones fallidas.
Many industrial activities generate effluents containing sulfur compounds, both as liquid or gaseous emissions, which are mainly treated through physical-chemical processes. Sulfate is generally present in wastewaters coming from paper, pharmaceutical, mining or food processing industries, among others. As such, sulfate is not a harmful compound, but if it is poured into rivers or sewage systems, an imbalance in the overall sulfur cycle can be generated. Inside this cycle, the last product after the reduction of sulfur compounds is hydrogen sulfide (H2S). This compound is corrosive, odorous and toxic at low concentrations. For these reasons, there is a need to develop environmentally friendly alternatives to valorize not only gaseous emissions, such as SO2 emissions, but also S-rich liquid effluents. In addition, a further recovery of elemental sulfur from these effluents could be obtained providing an opportunity to recover resources in the framework of the circular economy. With these premises, the SONOVA project, in which this thesis is enclosed, is based in the development of a comprehensive treatment process to valorize SOx and NOx from flue gases by economical, robust and environmentally friendly biological methods. It also takes into account the reuse of energy and resources along the process as well as residues valorization. The proposed process is based on a first double stage for selective absorption of SOx and NOx; a second biological step for reducing the sulfate from the first absorption stage to hydrogen sulfide (which is the focus of this thesis); and a third biological stage for the oxidation of hydrogen sulfide to elemental sulfur and its subsequent recovery. Biological-based systems, such as Up-flow Anaerobic Sludge Bed (UASB) reactors, have been developed and implemented world-wide to treat many types of wastewater and to produce biogas through anaerobic digestion. In this thesis, the use of an UASB reactor for the treatment of synthetic wastewater with sulfate was studied, specifically selecting crude glycerol as carbon source and electron donor. Both physical-chemical processes and molecular biology techniques were used to get a broad knowledge of the anaerobic process. The influence of possible inhibitions and competition between sulfate reducers and methanogens was studied in order to improve sulfate removal and sulfide production. It was observed that in long-term operations (after 200 days approximately) methanogens were washed out from the system and sulfate reducers colonized the reactor sludge. However, acetate accumulation was observed because of the disappearance of methanogens, leading to a loss of carbon source in the outlet of the reactor that could have been used to produce sulfide in the UASB. Long-term performances allow detecting further limitations of the system. A loss of granular structure and the growth of unidentified non-sulfate reducer, non-methanogenic biofilm was observed during UASB operations along this thesis. This biofilm, called slime substance along this thesis, was found to be a crucial factor affecting our system, conferring properties such as viscosity to the sludge. Consequently, problems related to mass transfer limitations could be observed, affecting as well, the sulfate reducing activity of the granules and leading to failure operations. Finally, since the accumulation of acetate could not be avoided, experiments were designed to pursue the enrichment of acetate degrading sulfate reducing bacteria in serum bottles, with the final objective of improving sulfidogenesis. In addition, isolation of potential acetate-utilizing sulfate reducers was also pursued. Unfortunately, a culture able to perform sulfate reduction with acetate was not developed during the enrichment experiments. Therefore, further research is needed to enhance the operation in terms of organic matter consumption and sulfide productivity in the long-term.
Abdoulmoumine, Nourredine. "Sulfate and Hydroxide Supported on Zirconium Oxide Catalysts for Biodiesel Production." Thesis, Virginia Tech, 2010. http://hdl.handle.net/10919/33873.
Повний текст джерелаMaster of Science
Hentati, Faiez. "Caractérisations structurales et propriétés rhéologiques des polysaccharides de deux algues marines tunisiennes : Cystoseira compressa et Jania adhaerens." Thesis, Université Clermont Auvergne (2017-2020), 2020. http://www.theses.fr/2020CLFAC003.
Повний текст джерелаCystoseira compressa and Jania adhaerens are two seaweeds widespread on the Tunisian coasts and were not exploited. They have been used as natural ingredients to produce new canned fish burgers prepared from minced fish of common barbel (Barbus barbus). In addition, this work led to the extraction of a fucoidan (CCF) and a sodium alginate (CCSA) as matrix polysaccharides of C. compressa. CCF (Mw=1.05 × 105 g/mol) was a sulfated (14.65%) heterogalactofucan composed of α-(1,3) and α-(1,4)-linked l-Fucp as main backbone, which could be branched (31.8%) in O-3 and O-4 positions by terminal monosaccharides and side chains. CCSA (Mw = 1 × 105 g/mol) was composed of 56% α-l-GulA (G) and 44% β-d-ManA (M) (M/G = 0.77). The CCSA linear backbone was constituted by 93% of homoblocks (FGG = 53% and FMM = 40%) and 6% of heteroblocks (FMG = 3% and FGM = 3%). Rheological and biological investigations showed that CCF and CCSA solutions exhibited shear-thinning and fluid-like viscoelastic behaviors with antioxidant properties. A sulfated xylogalactan-rich fraction (JSP) was extracted from J. adhaerens. JSP (Mw = 8.0 × 105 g/mol) was mainly constituted by the agaran disaccharidic repeating residues (→3)-β-d-Galp-(1,4)-α-l-Galp-(1→)n and (→3)-β-d-Galp-(1,4)-3,6-α-l-AnGalp-(1→)n mainly substituted on O-6 of (1,3)-β-d-Galp residues and in O-2 and O-3 positions of (1,4)-α-l-Galp residues by T-β-d-Xylp, methoxy and/or sulfate groups. JSP solutions displayed a shear-thinning behavior with a great viscoelasticity character, having weak gel properties
Ingram, Laura Jane. "The Synthesis of Sulfated Carbohydrates Using a Sulfate Protecting Group Strategy." Thesis, 2010. http://hdl.handle.net/10012/5437.
Повний текст джерелаSu, Chih-Mao, and 蘇旨茂. "Study of the Involvement of Highly Sulfated Heparan Sulfate on Japanese Encephalitis Virus Infection." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/76413263038391269579.
Повний текст джерела國防醫學院
生命科學研究所
91
Japanese encephalitis virus (JEV) infects a broad range of cell types in vitro, though little is known about the initial events of JEV infection. In the present study, we found that highly sulfated glycosaminoglycans (GAGs) are involved in infection of both neurovirulent (RP-9) and attenuated (RP-2ms) JEV strains. Competition experiments using highly sulfated GAGs, heparin and dextran sulfate, demonstrated an inhibition of JEV’s attachment and subsequent infection of BHK-21 cells. Treatment of target cells by a potent sulfation inhibitor, sodium chlorate, greatly reduced viral binding ability as well as infection, suggesting a critical role of GAGs’ sulfation status on the cellular surface in JEV infection. This phenomenon was confirmed by the manifestation of a distinct binding efficiency of JEV to the wild-type CHO cell line and its mutants with defects in GAG biosynthesis. We also demonstrated the binding of JEV particles and virus envelope glycoprotein to immobilized heparin beads. Furthermore, the addition of heparin suppressed the cytopathic effects induced by JEV infection in cultured cells. Our results establish that the highly sulfated form of GAGs on cell surfaces plays a determining role in the early stage of in vitro JEV infection.
LI, JYUN-YI, and 李俊毅. "Synthesis of Sulfated Trisaccharide Core Structure of TF-pLNH Sulfate III From Human Milk." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/q26p36.
Повний текст джерела國立中正大學
化學暨生物化學研究所
107
Human milk oligosaccharides are structurally diverse and unconjugated glycans. They are important to the infant growth since they can increase the amount of probiotics in small intestine. The pathological functions of sulfated human milk oligosaccharides are poorly understood since they are difficult to obtain. To get the sulfated oligosaccharides for future biological study, We have synthesized glycosyl acceptor (compound 9) and glycosyl donors (compound 12, compound 13, compound 16) to prepare trisaccharide (compound 20). Followed by selectively sulfonylation and functional group transformation, the core trisaccharide structure (compound 2) of TFpLNH sulfate III (1) was achieved. The compound 2 could extended by different glycosyltransferases and the glycans could applied for the investigation of pathological functions.
Wolff, Jeremy J. "Electron detachment dissociation of sulfated glycosaminoglycans." 2008. http://purl.galileo.usg.edu/uga%5Fetd/wolff%5Fjeremy%5F200805%5Fphd.
Повний текст джерела"Deactivation and regeneration of sulfated zirconia." Tulane University, 1998.
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