<p>Akrilamid (CASR No. 79-06-1) predstavlja veoma reaktivni, hidrosolubilni&nbsp;monomer za koji se smatra da ima toksične i potencijalno kancerogene efekte po&nbsp;zdravlje ljudi. &Scaron;tetne posledice akrilamida i njegovog jo&scaron; reaktivnijeg metabolita,&nbsp;glicidamida, su dokazane kod eksperimentalnih životinja i podrazumevale su&nbsp;neurotoksičnost, genotoksičnost i kancerogenost. Epidemiolo&scaron;ke studije rađene na&nbsp;ljudima pokazale su da akrilamid izaziva neurotoksične efekte, dok se genotoksičnost i&nbsp;kancerogenost jo&scaron; smatraju potencijalnim efektima, a zasnivaju se na podacima koji su&nbsp;dobijeni u okviru istraživanja na laboratorijskim životinjama. Njegove &scaron;tetne posledice&nbsp;na jetru, posebno kod mladog organizma, jo&scaron; uvek nisu dovoljno istražene.</p><p>Akrilamid se spontano formira u hrani koja je bogata ugljenim hidratima, tokom&nbsp;termičke obrade namirnica na visokim temperaturama. Ovaj monomer se formira&nbsp;tokom tzv. neenzimatske Mallard-ove reakcije, kojom se dobijaju smeđe komponente&nbsp;u hrani. U namirnicama ovaj monomer se formira reakcijom između redukujućih&nbsp;&scaron;ećera (uglavnom glukoze ili fruktoze) i aminokiseline (dominantno asparagina).</p><p>Imajući na umu da je jetra centralni organ za metabolizam akrilamida, ovo&nbsp;istraživanje &nbsp;je imalo za cilj da ispita glavne histolo&scaron;ke i biohemijske promene na jetri&nbsp;juvenilnog organizma pacova, nakon njegove subhronične ekspozicije akrilamidu.&nbsp;Istraživanje je &nbsp;rađeno na 3 eksperimentalne grupe peripubertalnih/juvenilnih mužjaka&nbsp;Wistar pacova, od kojih su dve bile tretirane vodenim rastvorom akrilamida u dozi od&nbsp;25 ili 50 &nbsp;mg/kg telesne mase, dok je treća grupa služila kao kontrola i primala&nbsp;destilovanu vodu. Životinje su bile tretirane oralno, putem gavaže, 5 dana nedeljno,&nbsp;tokom 3 nedelje. Nakon 24 h od poslednjeg tretmana, životinje su uvedene u etarsku &nbsp;anesteziju i dekapitovane, a zatim su prikupljeni krv i uzorci tkiva jetre.</p><p>Tkivo jetre je uzeto iz srednjeg lobusa, fiksirano u 10% neutralnom puferisanom &nbsp;formalinu tokom 24 h i obrađeno prema standardnom protokolu za parafinsko kalupljenje. Ukalupljeni uzorci jetre su zatim isečeni na serijske preseke tkiva debljine&nbsp;5 &micro;m, a zatim bojeni histohemijskim i imunohistohemijskim metodama. Uzorci krvi su&nbsp;pripremljeni za serolo&scaron;ku analizu.&nbsp;</p><p>Histolo&scaron;ka analiza preseka bojenih hematoksilin-eozin (H&amp;E) metodom nije &nbsp;zabeležila prisustvo značajnih razlika u op&scaron;toj arhitekturi jetre i njenoj lobularnoj &nbsp;organizaciji među eksperimentalnim grupama. Stereolo&scaron;ka analiza je ukazala na &nbsp;<br />mikrostrukturne promene kod hepatocita i jetrinih sinusoida. Rezultati sugeri&scaron;u, na&nbsp;dozno-zavisno povećanje volumena hepatocita, njihove citoplazme i nukleusa, i doznozavsino smanjenje volumena sinusoida, u odnosu na kontrolne uzorke jetre.</p><p>Analiza glikogena je rađena na presecima jetre bojenim metodom Periodic acid&ndash;<br />Schiff-a (PAS), gde se uočilo smanjenje količine glikogena u grupi tretiranoj nižom &nbsp;dozom akrilamida, dok je u grupi tretiranoj većom dozom uočena njegova&nbsp;<br />akumulacija, u odnosu na kontrolne životinje.</p><p>Imunopozitivnost hepatocita na marker proliferacije, Ki-67, bila je smanjena u&nbsp;grupi pacova tretiranoj nižom dozom, a bila povećana u grupi tretiranoj većom dozom&nbsp;akrilamida pri komparaciji sa kontrolom. Stereolo&scaron;ki nalazi su potvrdili inicijalnu&nbsp;histolo&scaron;ku analizu.</p><p>Imunopozitivnost hepatocita na marker apoptoze, Caspase 3, je bila smanjena&nbsp;<br />kod obe grupe životinja tretiranih akrilamidom u odnosu na kontrolu. Nasuprot tome,&nbsp;<br />imunopozitivnost neparenhimskih ćelija jetre, pretežno Kupffer-ovih ćelija, je bila&nbsp;<br />uvećana u obe tretirane grupe pri komparaciji sa kontrolom.</p><p>Imunopozitivnost Kupffer-ovih ćelija na marker CD68 je bila smanjena u&nbsp;uzorcima jetre kod oba tretmana akrilamidom u odnosu na kontrolu.</p><p>Populacija mastocita, prikazana toluidine-blue (TB) metodom bojenja, bila je&nbsp;uvećana &nbsp;kod obe grupe pacova tretiranih akrilamidom u poređenju sa kontrolom.&nbsp;Povećanje brojnosti ovih ćelija je bilo posebno prominentno kod njihove degranulisane &nbsp;subpopulacije. Stereolo&scaron;ka analiza je potvrdila histolo&scaron;ke nalaze.&nbsp;</p><p>Serumska analiza je pokazala uvećanu aktivnost aspartat aminotrasferaze (AST) i&nbsp;<br />smanjenu aktivnost alanin aminotrasferaze (ALT) kod obe grupe životinja tretiranih &nbsp;<br />akrilamidom u odnosu na kontrolu. Aktivnost alkalne fosfataze (ALP) je bila uvećana&nbsp;<br />u grupi tretiranoj nižom dozom, a smanjena u grupi tretiranoj većom dozom&nbsp;<br />akrilamida, u odnosu na kontrolu. Vrednosti koncentracije ukupnih serumskih proteina&nbsp;kao i koncentracije C reaktivnog proteina (CRP) nisu pokazale značajnije promene&nbsp;među eksperimentalnim grupama.</p><p>Oba akrilamidna tretmana su izazvala gubitak telesne mase kod tretiranih&nbsp;pacova, u odnosu na kontrolne životinje.&nbsp;Postojeći podaci ukazuju prominentni hepatotoksični potencijal akrilamida koji može&nbsp;poremetiti mikrostrukturne osobine i funkcionalni status hepatocita kod jetre mladog&nbsp;organizma. Akrilamid može značajno poremetiti funkcionalnost jetre, obzirom da se&nbsp;promene na celularnom nivou mogu relativno brzo odraziti na nivo tkiva, a kasnije&nbsp;ugroziti i homeostazu celog organizma.</p> / <p>Acrylamide&nbsp; (CASR No. 79-06- 1)&nbsp; is highly reactive, water-soluble monomer which is considered as toxic and potentially cancer causing chemical to humans. Adverse health effects regarding acrylamide and its more reactive metabolite,glycidamide, were detected in experimental animals, and&nbsp; included neurotoxicity, genotoxicity, and&nbsp;&nbsp; carcinogenicity.&nbsp; Human epidemiological studies claim that acrylamide has neurotoxic effects, while&nbsp; genotoxicity and carcinogenicity are considered as&nbsp; potential human health risks only on the basis of animal studies. Its harmful effects on the liver, especially in a young organism, are still to be elucidated.</p><p>Acrylamide&nbsp; is spontaneously formed in&nbsp; carbohydrate-rich food during high-temperature&nbsp; processing. It is&nbsp; formed during heat-induced non-enzymatic reaction, also known as&nbsp; the Maillard browning reaction, between reducing sugars (glucose and fructose), and free amino acids (mainly asparagine).</p><p>Having in mind&nbsp; that&nbsp; acrylamide&nbsp; metabolism takes place in a liver,&nbsp; the study aimed to investigate the main histological and&nbsp; biochemical changes in the liver of juvenile rat following subchronic acrylamide intoxication. Study was performed on peripubertal/juvenile male Wistar rats, divided in 3 experimental groups, two of which were treated with acrylamide in doses of 25 or 50 mg/kg of body weight, while the third group served as the control and received distilled water. Animals were treated orally, via gavage, 5 days a week, during 3 weeks. Animals&nbsp; were anesthetized by&nbsp;&nbsp; ether inhalation and decapitated 24 hrs after the last treatment.</p><p>Liver tissue was sampled from the middle lobe, fixed in&nbsp; 10% neutral&nbsp; buffered formalin for 24 hrs,&nbsp; routinely processed for paraffin&nbsp; embedding&nbsp; and cut into 5-&micro;m thick serial sections for subsequent histochemical and immunohistochemical staining.Blood samples were collected for subsequent biochemical analysis .</p><p>Histological examination of haematoxylin and eosin (H&amp;E) stained sections did not point to any major alteration in main in liver lobular architecture or organization among the experimental groups. Stereological analysis revealed a microstructural changes in hepatocytes and liver sinusoids. The analysis detected a dose-dependant increase in the volume of hepatocytes, their cytoplasm and nuclei, and dose-dependant decrease in the volume of liver sinusoids compared to the control, respectively.</p><p>Glycogen analysis was performed on Periodic acid&ndash;Schiff (PAS) stained sections which showed glycogen reduction in the low-dose group, and its accumulation in the high-dose group, compared to the control, respectively.</p><p>Imunopositivity in hepatocytes for Ki-67 protein, a known marker for proliferation, showed a decrease in low-dose group, while in high- dose group was detected its increase compared to the control, respectively. Stereological analysis confirmed initial histological observation.</p><p>Caspase 3 immunopositivity, a known marker for apoptosis, proved to be decreased in hepatocytes in both acrylamide-treated groups when compared to the control. One the other hand, immunopositivity was increased in non-parenchymal&nbsp; cell, predominantly in Kupffer cells, in comparison to the control. Immunopositivity for CD68, a marker for Kupffer cells, proved to be decreased in both acrylamide-treated groups when compared to the control.</p><p>Population of the mast cells, visualized on toluidine blue (TB) stained sections, showed its increase in both acrylamide-treated groups, in comparison to the control. The increase was especially prominent regarding a degranulated subpopulation of these cells. Subsequent stereological analysis confirmed histological findings.</p><p>Serum analysis showed increased&nbsp; activity of&nbsp; aspartate aminotransferase (AST), and decreased&nbsp; activity&nbsp; of alanine aminotransferase (ALT) in&nbsp; both AA-treated groups, while the&nbsp; activity&nbsp; of alkaline phosphatase (ALP)&nbsp; was increased in low-dose, but&nbsp;&nbsp; decreased in high- dose group compared to the control, respectively.&nbsp; The concentration of total serum proteins as well as concentration of C reactive protein (CRP) did not show any major changes among the experimental groups.</p><p>Body weight measurements showed that all acrylamide-treated rats lost their body weight as opposed to the control rats whose body mass increased.</p><p>Present results suggest a prominent hepatotoxic potential of acrylamide which might alter the microstructural features and functional status in hepatocytes of&nbsp; immature liver.&nbsp; Acrylamide may cause significant perturbation in liver functionality which may be reflected from cellular to the tissue level, thereby endangering the whole body&rsquo;s homeostasis.</p>

Doctor of Philosophy / Department of Chemistry / Stefan Bossmann / Tris-homoleptic ruthenium(II)-quaterpyridyl and quaterpyridinium complexes, with +8 and +14 charge were synthesized by utilizing high pressure reaction pathway. These complexes have diameters ranging from 1.82 to 4.55 nm according to the molecular modeling calculations. These ruthenium complexes are highly luminescent and contain long excited state life times. The novel ruthenium(II)-quaterpyridinium complexes exhibit superior reactivity as sensitizer-relay-assemblies (SRA‟s) in sacrificial systems for water and carbon dioxide reductions, while harvesting the ultraviolet- and most of the visible fraction of the incident solar spectrum. Ru(II)-quaterpyridinium complexes and Pd/TiO2 catalysts were successfully used as the catalytic system for the photo catalytic reduction of water and carbon dioxide to hydrogen and methane respectively. Phosphonate-tethered Ru(II)-quaterpyridinium complexes were synthesized from Ru(II)-tris-quaterpyridyl complexes. These complexes form stable adhesive layers on indium tin oxide (ITO) electrodes. A series of differential pulse voltammetry experiments were carried out to measure the ground state and excited state redox potentials of all the Ru(II)quaterpyridinium complexes. The reductive potentials obtained were compared with the reductive potentials of CO2 to CH4 and H2O to H2 reductions. The measurements obtained from the experiments confirmed that it is possible to thermodynamically oxidize water and reduce CO2 by using phosphonate-tethered Ru(II)-quaterpyridinium complexes. These complexes are successfully utilized as prototypes for mycobacterial channel blockers. The Ru(II) complexes show distinct changes in their luminescence spectra when bound to the porin MspA from M. smegmatis, which is a non-pathogenic relative of M. tuberculosis. By using HPLC, we have determined binding constants of the Ru(II)-complexes to MspA in phosphate buffer (0.05 M, pH = 6.8) ranging from 5.2 x 109 M-1 (Ru-C2) to 1.8 x 109 M-1 (Ru-C4). Our findings indicate that channel blocking is a promising treatment strategy for mycobacterial infections. Poly-N-isopropyl-acrylamide/acetic acid copolymers were synthesized and characterized by elemental analysis and gel permeation chromatography. The average composition of the copolymers determined from CHN analysis is in excellent correlation with the feed composition indicating that the radical polymerization process is indeed statistical. Crosslinking of individual polymer chains permitted the generation of ultraflat layers on Mica surfaces by a simple spin-casting procedure, which are able to host the mycobacterial channel protein MspA, while retaining its channel function.

O consumo de produtos da reação de Maillard (PRM) formados em alimentos contribui para o aumento dos níveis séricos de produtos finais de glicação avançada, que, por sua vez, estão associados à fisiopatologia e progressão do diabetes, de doenças cardiovasculares e neurodegenerativas. A formação de PRM em alimentos e sistemas modelo-alimento está bem documentada, mas informações sobre os efeitos de diferentes métodos de cocção e uso de receitas são escassas, especialmente para carne vermelha. É importante avaliar se o controle das condições de cocção domésticas pode afetar a formação de PRM em carne, um alimento amplamente consumido. O objetivo deste trabalho foi estudar a formação dos PRM: furosina, carboximetillisina, acrilamida e compostos fluorescentes em carne bovina submetida a técnicas de cocção por calor úmido e calor seco. Hambúrgueres com 50 g de coxão mole (Semimembranosus) moído e 1% de sal de cozinha foram grelhados e empanados e fritos até atingir as temperaturas internas: 60&#176;, 70&#176;, 80&#176;, 90&#176; e 100&#176;C; cozidos por fervura em água até 60&#176;, 70&#176;, e 80&#176;C; e assados a 180&#176;, 240&#176; e 300&#176;C por 30 min. Os produtos da fase inicial da RM predominaram nas carnes grelhadas e empanadas e fritas em temperatura menor que 90 &#176;C, acima de 90 &#176;C ocorreu a degradação de furosina, associada à formação acentuada de compostos fluorescentes e a etapa intermediária da RM está em curso, predominantemente; a formação do marcador da fase avançada da RM (CML) ocorreu apenas na condição térmica mais severa, a carne assada a 300 &#176;C por 30 minutos. Condições de cocção que resultaram em grande aceitação da cor e baixa formação de PRM de fase avançada foram encontradas para carne bovina e podem ser utilizadas em orientações para pacientes com diabetes em ensaios clínicos futuros. / The ingestion of Maillard reaction products (MRP) from foods seems to be correlated with serum advanced glycation end products (AGEs) levels in humans. AGEs are associated with pathological effects in vivo, specifically diabetes complications, cardiovascular and neurodegenerative diseases. Substantial amount of data about MRP content in individual food products and model systems can be found, but there is a lack of information regarding the MRP generation during home cooking, especially for red meat. It is of interest to evaluate whether the control of home cooking conditions can effectively affect MRP content in beef, a food consumed worldwide. The influence of home cooking methods employing dry-heat and boiling on the generation of furosine, carboxymethyllysine, acrylamide and fluorescent compounds in beef was investigated in this study. Fifty grams of raw ground meat (Semimembranosus) with 1.0% of NaCl was made into a hamburger shape and grilled or breaded and fried: meat was cooked to an internal temperature of 60&#176;, 70&#176;, 80&#176;, 90&#176; and 100&#176;C; boiled: meat was cooked to 60&#176;, 70&#176;, and 80&#176;C. For baking, the oven was set at 180&#176;, 240&#176; and 300&#176;C for 30 minutes. Grilling and frying hamburgers to an internal temperature below 90 &#176;C mainly generated furosine. When the temperature reached 90 &#176;C and 100 &#176;C, furosine content decreased and fluorescent compounds increased exponentially. Baking meat at 300 &#176;C, the most severe heat treatment studied, resulted in the formation of carboxymethyllysine. Home cooking conditions leading to low MRP generation and pleasant colors were obtained and could be used to guide diabetic patients in clinical studies.

O consumo de produtos da reação de Maillard (PRM) formados em alimentos contribui para o aumento dos níveis séricos de produtos finais de glicação avançada, que, por sua vez, estão associados à fisiopatologia e progressão do diabetes, de doenças cardiovasculares e neurodegenerativas. A formação de PRM em alimentos e sistemas modelo-alimento está bem documentada, mas informações sobre os efeitos de diferentes métodos de cocção e uso de receitas são escassas, especialmente para carne vermelha. É importante avaliar se o controle das condições de cocção domésticas pode afetar a formação de PRM em carne, um alimento amplamente consumido. O objetivo deste trabalho foi estudar a formação dos PRM: furosina, carboximetillisina, acrilamida e compostos fluorescentes em carne bovina submetida a técnicas de cocção por calor úmido e calor seco. Hambúrgueres com 50 g de coxão mole (Semimembranosus) moído e 1% de sal de cozinha foram grelhados e empanados e fritos até atingir as temperaturas internas: 60&#176;, 70&#176;, 80&#176;, 90&#176; e 100&#176;C; cozidos por fervura em água até 60&#176;, 70&#176;, e 80&#176;C; e assados a 180&#176;, 240&#176; e 300&#176;C por 30 min. Os produtos da fase inicial da RM predominaram nas carnes grelhadas e empanadas e fritas em temperatura menor que 90 &#176;C, acima de 90 &#176;C ocorreu a degradação de furosina, associada à formação acentuada de compostos fluorescentes e a etapa intermediária da RM está em curso, predominantemente; a formação do marcador da fase avançada da RM (CML) ocorreu apenas na condição térmica mais severa, a carne assada a 300 &#176;C por 30 minutos. Condições de cocção que resultaram em grande aceitação da cor e baixa formação de PRM de fase avançada foram encontradas para carne bovina e podem ser utilizadas em orientações para pacientes com diabetes em ensaios clínicos futuros. / The ingestion of Maillard reaction products (MRP) from foods seems to be correlated with serum advanced glycation end products (AGEs) levels in humans. AGEs are associated with pathological effects in vivo, specifically diabetes complications, cardiovascular and neurodegenerative diseases. Substantial amount of data about MRP content in individual food products and model systems can be found, but there is a lack of information regarding the MRP generation during home cooking, especially for red meat. It is of interest to evaluate whether the control of home cooking conditions can effectively affect MRP content in beef, a food consumed worldwide. The influence of home cooking methods employing dry-heat and boiling on the generation of furosine, carboxymethyllysine, acrylamide and fluorescent compounds in beef was investigated in this study. Fifty grams of raw ground meat (Semimembranosus) with 1.0% of NaCl was made into a hamburger shape and grilled or breaded and fried: meat was cooked to an internal temperature of 60&#176;, 70&#176;, 80&#176;, 90&#176; and 100&#176;C; boiled: meat was cooked to 60&#176;, 70&#176;, and 80&#176;C. For baking, the oven was set at 180&#176;, 240&#176; and 300&#176;C for 30 minutes. Grilling and frying hamburgers to an internal temperature below 90 &#176;C mainly generated furosine. When the temperature reached 90 &#176;C and 100 &#176;C, furosine content decreased and fluorescent compounds increased exponentially. Baking meat at 300 &#176;C, the most severe heat treatment studied, resulted in the formation of carboxymethyllysine. Home cooking conditions leading to low MRP generation and pleasant colors were obtained and could be used to guide diabetic patients in clinical studies.

This thesis focuses on the development of new stationary phases for use in hydrophilic interaction liquid chromatography using TRIS-based and phosphorylcholine typed monomers and porous silica particles as starting substrates. In this thesis, several ways of polymerizing highly hydrophilic mono­mers onto pore surfaces of silica supports are described, based on several “grafting from” schemes. “Controlled/living” radical polymerizations including atom transfer radical polymerization (ATRP) and iniferter-mediated polymerization in conjunction with conventional free radical polymerization are demonstrated to be successful tools for grafting different hydrophilic monomers (polyhydroxyl and phosphorylcholine [meth]acrylamide/acrylates) onto the silica surfaces. Reaction solvents are proven to play an essential role to achieve efficient graft polymerization of activated silica surfaces with these amphiphilic vinylic monomers, which is difficult because of their restricted access to the activated surface in solvents that can be used because of solubility constraints. Two tentacle TRIS-based polymer grafted silica, namely TRIS-WAX – TRIS functionality bonded to silica via a C–N–C imine bond and TRIS-Amide – TRIS bonded to silica via an amide bond, prove to be useful as stationary phases for hydrophilic interaction chromatography (HILIC).The TRIS-WAX exhibits a mixed mode hydrophilic partitioning and weak anion exchange (HILIC/WAX) retention mechanism while retention by hydrophilic partitioning is the dominant mechanism on the neutral TRIS-Amide phase which lacks weak anion exchange (WAX) properties. Interestingly, both these phases have selectivities that are radically different from most commercial HILIC stationary phases. Finally, a method is demonstrated for synthesizing a stratified (graft-copolymerized) silica material based on N,N′-methylenebisacrylamide and 2-methacryloyloxyethyl phosphorylcholine (MPC) using a “controlled/living” photoiniferter-mediated polymerization from the N,N-diethyldithiocarbamate iniferter moiety immobilized silica surfaces. This polymerization method proves to be successful for graft-blockcopolymerization of different highly hydrophilic monomers onto the activated surfaces of porous silica. In this way, silica surfaces are grafted with a cross-linked amide-based hydrogel, on top of which a tentacle zwitterionic phosphorylcholine-typed layer is synthesized. The resulted material proves to be useful for HILIC separations and possesses different selectivity for the tested organic acids compared to that of commercial ZIC-cHILIC stationary phase.

The main objective of this study was to determine the effects of batters containing various flour types and frying methods on physical and chemical properties of chicken fingers. To determine the effects of different flour types, 30 % of the corn and wheat flour mix in control batter was replaced with chickpea, rice or soy flours. Frying was performed in microwave oven at 365 W (70 %) power level and at 180&amp / #61617 / 1&deg / C for different times. Samples were also fried in a conventional fryer at 180&amp / #61617 / 1&deg / C for comparison. The properties that were measured were coating pick-up and moisture content, oil content, color, hardness, porosity and acrylamide content of fried samples. In addition, microstructural analysis of batters and temperature distribution of fried samples during cooling were performed. Moisture content of chicken fingers decreased whereas the darkness, porosity and hardness of samples increased with increasing microwave frying time. Using microwaves decreased frying time by 70 %. Samples fried for 1.5 min using microwave provided similar moisture and oil contents in the coating part as compared to conventionally fried ones for 5min. However, the chicken part of microwave fried sample had lower moisture content. Lighter colored samples with higher porosity and lower hardness values were obtained with microwave frying. In microwave frying, soy flour addition to batter formulation decreased the moisture loss and oil absorption as compared to control by 19.3% and 20.7%, respectively. The lowest hardness, the highest porosity and oil content were obtained with the addition of chickpea flour. Flour type was not found to be effective on acrylamide content. Microwave frying provided lower acrylamide content as compared to those fried conventionally for all types of flours. The reduction in acrylamide level was the highest (34.5%) for rice flour containing batter. Color parameters of chicken fingers were not found to be a reliable indicator of acrylamide levels. Different types of frying method and flours used in batter formulation resulted in differences in the microstructure of fried batter. Variations in internal temperature distribution during cooling increased with frying time in both microwave and conventional frying. The sample fried in microwave oven for 1.5 min had a more nonuniform temperature distribution.

Das Ziel der Arbeit bestand darin, ein verbessertes Verfahren zur Ausbildung einer Polyurethanschicht mit poröser Kapillarstruktur zu erarbeiten. Die Fällung (Koagulation) einer Polyurethanlösung erfolgt durch kontrollierte Freisetzung von Fällmittel aus einem zugesetzten, thermisch sensiblen und porös umhüllten Hydrogel. Bei Erwärmung auf eine stoffspezifische Temperatur setzt das Hydrogel Wasser frei, das die Fällung initiiert. Gegenüber der Fällung in einem Fällbad erzielt diese Verfahrensweise deutliche Verbesserungen. Die umhüllten Gele wurden mit Hilfe rheologischer, thermoanalytischer und weiterer Untersuchungsmethoden umfassend charakterisiert. Dadurch gelang es, eine Hüllenstruktur auszuwählen, die den spontanen Austausch von Löse- und Fällmittel verhindert und gleichzeitig die Wasserfreisetzung gewährleistet.

No description available.

Submitted by GUSTAVO HENRIQUE GRAVATIM COSTA null (ghg_costa@hotmail.com) on 2016-01-13T19:55:02Z No. of bitstreams: 1 Tese Doutorado - Corrigido.pdf: 5386530 bytes, checksum: 1106058657587336c65f66d43bc3cb4a (MD5) / Approved for entry into archive by Ana Paula Grisoto (grisotoana@reitoria.unesp.br) on 2016-01-14T11:57:25Z (GMT) No. of bitstreams: 1 costa_ghg_dr_jabo_int.pdf: 5386530 bytes, checksum: 1106058657587336c65f66d43bc3cb4a (MD5) / Made available in DSpace on 2016-01-14T11:57:25Z (GMT). No. of bitstreams: 1 costa_ghg_dr_jabo_int.pdf: 5386530 bytes, checksum: 1106058657587336c65f66d43bc3cb4a (MD5) Previous issue date: 2015-12-18 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Atualmente há crescente demanda do mercado consumidor de alimentos por produtos cada vez mais seguros à saúde humana. Entre estes, destaca-se o açúcar, que é amplamente consumido pela população mundial. Durante o processo de produção, são adicionados polieletrólitos sintéticos a base de acrilamida, objetivando a rápida sedimentação de impurezas presentes no caldo de cana durante a etapa de clarificação. Considerando-se que a molécula constituinte deste insumo pode ficar retido no cristal de açúcar, sua utilização deve ser controlada, uma vez que apresenta ações cancerígenas e neurotóxicas ao ser humano. Neste contexto, destacam-se o biomoléculas naturais que apresentam ação coagulante, como a proteína presente nas folhas e sementes da moringa. Neste sentido, o objetivo do trabalho foi avaliar o os reflexos do emprego de extratos de folhas e sementes de moringa, como auxiliares de sedimentação na clarificação do caldo de cana, na produção de açúcar e etanol. O experimento foi realizado no Laboratório de Tecnologia do Açúcar e do Álcool da FCAV/UNESP. O experimento foi realizado em 6 etapas. A primeira foi constituída pelo estudo de técnicas de extração da proteína presente na semente. Na segunda, realizou-se caracterização da proteína extraída. A terceira etapa derivou do teste de diferentes dosagens dos extratos na clarificação do caldo. A seguir realizou-se experimento comparativo entre os extratos de sementes e folhas de moringa, com floculante sintético comercial, floculante orgânico comercial, e tratamento testemunha, caracterizando-se o processe de clarificação do caldo e qualidade do açúcar produzido. A última etapa foi constituída pelo uso do melaço residual da produção de açúcar e de caldo clarificado com os 5 floculantes, como substrato para a produção de etanol. Observou-se que a utilização de solução a base de CaCl2 0,1mol/L resultou em maiores extrações de proteínas em comparação ao uso de soluções a base de KCl, MgCl2 e somente água destilada. Caracterizando-se a proteína da semente, verificou-se peso molecular inferior a 14KDa e duas diferentes biomoléculas presentes no extrato. Avaliando-se diferentes doses, determinou-se os valores de 100, 250, 500, 1300mg/L para os extratos a base de MgCl2, água, KCl e CaCl2, respectivamente; sendo que no teste de comparação entre estes, o extrato a base de CaCl2, apresentou os melhores resultados. De modo geral, os floculantes não apresentam influência direta sobre as caraterísticas do açúcar produzido, e sobre o processo fermentativo. Conclui-se que o extrato de sementes de moringa pode ser utilizado como floculante do caldo de cana para produção de açúcar e etanol. / There are currently increasing demands of the consumer market for food products ever safer to human health. Among these, it stands out sugar, which is widely consumed by the world population. During the production process, synthetic polyelectrolytes are added to the acrylamide-based, aimed at rapid sedimentation of impurities present in the juice of sugar cane during the clarification step. Considering that the constituent molecule of this input may be trapped in the crystal sugar, its use should be controlled, as it features carcinogenic and neurotoxic actions to humans. In this context, we highlight the natural biomolecules that have coagulant action, as this protein in the leaves and seeds of Moringa. In this sense, the objective of this study was to evaluate the reflections of leaf extracts of employment and moringa seeds, such as sedimentation aids in clarifying sugarcane juice, the sugar and ethanol. The experiment was carried out in Sugar Technology Laboratory and Alcohol FCAV/UNESP. The experiment was carried out in 6 steps. The first study was set up by extraction techniques of protein present in the seed. The second was held characterization of the extracted protein. The third step of the test derived from different dosages of the extracts in clarifying the broth. The following comparative experiment was carried out between extracts of seeds and moringa leaves with commercial synthetic flocculant, commercial organic flocculant, and control treatment, characterizing the process of clarifying the broth and quality of the sugar produced. The last step was formed by the use of the residual molasses from sugar production and clarified broth with 5 flocculants, as a substrate for ethanol production. It was observed that using the base solution of CaCl2 0.1 mol/L resulted in higher protein extraction compared to the use of solutions based KCl, MgCl2 and only distilled water. Characterised seed protein, it was found molecular weight less than 14KDa and two different biomolecules present in the extract. Evaluating different doses, values were determined in 100, 250, 500, 1300mg/L for extracts the base MgCl2, water, KCl and CaCl2, respectively; wherein the comparison test among these, the extract CaCl2 base, showed the best results. In general, the flocculants have no direct influence on the characteristics of the produced sugar, and the fermentation process. We conclude that the moringa seed extract can be used as flocculant of sugarcane juice to produce sugar and ethanol.

Depuis le milieu du 20ème siècle, les techniques de récupération assistée du pétrole (RAP) ont été beaucoup utilisées afin d’améliorer le rendement d’extraction du pétrole brut. Des polyacrylamides modifiés hydrophobiquement ont montré des propriétés intéressantes en tant que modificateurs de rhéologie en vue d’une application en RAP. Cependant, la synthèse de polymères hydrosolubles comportant des segments hydrophobes le long de la chaîne est un défi puisque les monomères hydrophiles et hydrophobes sont rarement miscibles dans le même solvant. Le but de cette thèse a été de développer des copolymères à base d’acrylamide pouvant ensuite être utilisés en RAP. Au cours de l’extraction du pétrole, des polymères possédant des longues chaînes sont mélangés à l’eau puis injecté dans le puits afin de pousser le pétrole brut en dehors de celui-ci. Le polymère a alors pour rôle d’accroître la viscosité de l’eau de sorte qu’elle puisse déplacer plus efficacement le pétrole hors du réservoir. Au cours de cette thèse, la technique RAFT/MADIX a été combinée à la polymérisation micellaire dans le but de synthétiser de nouveaux copolymères associatifs d’architectures contrôlées et possédant de nombreux blocs hydrophobes distribués le long de la chaîne. En phase aqueuse, les segments hydrophobes s’associent et forment un réseau viscoélastique résultant en une augmentation de la viscosité. La combinaison de RAFT/MADIX avec la polymérisation micellaire nous permet également de limiter la dérive en composition observée en polymérisation micellaire conventionnelle. Dans un premier temps, l’étude de l’effet des monomères et de sels sur le comportement des micelles de tensio-actif a montré que la présence de NaAMPS gouverne le procédé de micellisation du SDS par rapport à l’acrylamide. Cette étude a également prouvé qu’il est possible de prévoir l’évolution du NH en fonction de la composition du milieu réactionnel au cours de la synthèse. La compréhension des interactions tensio-actif-monomères permet ainsi de prévoir la microstructure du polymère. Dans un second temps, il a été démontré que les polymères associatifs synthétisés ici se comportent comme des chaînes vivantes et peuvent être étendus avec de l’acrylamide pour former des polymères à bloc de haute masse molaire. L’addition d’un sel monovalent tel que le chlorure de sodium (NaCl) s’est révélée un outil efficace pour contrôler la microstructure du polymère, rendant possible le passage d’une composition de type gradient vers une composition plus homogène (rmonomères hydrophiles/tBS proche de 1). Enfin, l’analyse des relations structure-propriété a montré que tous les polymères synthétisés possèdent un comportement associatif et accroissent la viscosité de l’eau comparé à l’homopolyacrylamide. La présence de NaAMPS dans la chaîne diminue fortement la viscosité du polymère alors qu’elle n’est pas affectée par celle du chlorure de sodium. Le polymère présentant les meilleures propriétés en vue d’une application en RAP est P(Am90-co-AMPS10-co-(Am/NaCl)10-co-tBS1). L’utilisation de NaCl assure de bonnes propriétés rhéologiques tandis que le NaAMPS favorise la solubilité du copolymère en solution aqueuse. / Since the middle of the 20th century, enhanced oil recovery (EOR) techniques have been used to improve the extraction of crude oil. Hydrophobically modified polyacrylamides have shown great properties as rheology modifiers for EOR purposes. However, the synthesis of water-soluble polymers containing hydrophobic segments along the backbone is challenging as hydrophilic and hydrophobic monomers are rarely soluble in the same solvent. The aim of this project was to develop acrylamide-based copolymers for enhanced oil recovery (EOR). In this process, long chain polymer molecules are mixed with water and injected into the oil field in order to drive the oil out of the well. The polymer serves to increase the viscosity of the water, making it more effective at displacing the oil. In this thesis, RAFT/MADIX technique has been combined with micellar polymerization in order to synthesize new associative copolymers with controlled architectures and numerous hydrophobic blocks distributed along the backbone. The associations generate a viscoelastic network in aqueous media resulting in a viscosity increase. The combination of RAFT/MADIX with micellar polymerization allows us to limit the compositional drift observed in conventional micellar polymerization. First, the study of the effect of monomers and salts on the behavior of surfactant micelles has shown that the influence of NaAMPS dominates that of acrylamide in its effect on the micellization behavior of SDS. This study has proven that it is possible to predict how NH would vary depending on the composition of the reactive medium during the synthesis. Understanding the surfactant-monomer interactions thus enables prediction of the microstructure of the polymer. In a second step, it has been demonstrated that the associative polymeric chains were living chains and could be further extended to high molar masses with acrylamide. Increasing the content of NaAMPS in the hydrophilic backbone led to a significant increase in the reactivity ratio. The addition of monovalent salt (especially NaCl) is a useful tool to control the polymer microstructure, enabling switching between a gradient-type composition and a more homogeneous one (rhydrophilic monomers/tBS close to 1). Finally, the examination of structure-property relationships of the associative polymers has highlighted that all polymers displayed associating properties as well as enhanced viscosity compared to homopolyacrylamide. The polymer viscosity strongly decreased upon incorporation of NaAMPS within the backbone while it was unaffected by the presence of NaCl during the synthesis. The polymer displaying the best properties for use in EOR is P(Am90-co-AMPS10-co-(Am/NaCl)10-co-tBS1). The use of NaCl ensures good rheological properties while AMPS enhances the solubility of the copolymer.