This doctoral thesis studies the properties and behaviour of phase-separated hydrogels. These can be prepared by interaction of polyelectrolytes with oppositely charged surfactants. Negatively charged polysaccharide hyaluronan and cationic surfactant carbethopendecinium bromide (Septonex), whose properties, behaviour and utilization are described in the first two chapters of theoretical part, were selected for this role. Hyaluronan is naturally-occuring in living organisms and is known for his specific targeting to the tumour cells. Septonex is used as antiseptic and disinfectant. Experimental part of this work is focused on examination of the structure and behaviour of these types of hydrogels especially from rheological point of view. The crucial part of this study was to establish mechanical properties and their dependence on environment. This led to design further studies. Structural analysis was held using the methods of ATR-FTIR, ionic chromatography and ICP-OES helping to measure the inner content of entry materials in the gels and supernatants respectively. The last chapter deals with antimicrobial activity. The results of this study indicate a potential usage of these substances in the field of medical applications.

This diploma thesis is focused on preparation of perovskite methylammonium lead bromide thin film layers and also thin film layers of its precursors, namely methylammonium bromide and lead(II) bromide, by spin-coating from the solution; and optical characterisation of the prepared thin film layers by UV-VIS spectroscopy and spectroscopical ellipsometry. Methylammonium bromide does not absorb in visible nor ultraviolet region, the maximum absorption of lead(II) bromide occurred in ultraviolet region, methylammonium lead bromide absorbs in visible region. Optical band gaps were determined by Tauc method to (3,5 ± 0,1) eV for lead(II) bromide and 2,15 eV, respectively 2,25 eV for perovskite. Refractive indices and extinction coefficients were determined by ellipsometry in range of wavelengths from 290 nm to 830 nm and their dependence with layer thickness was discussed. Ellipsometry model used in this thesis consist on Tauc-Lorentz oscillators for methylammonium bromide, methylammonium lead bromide and partially for lead(II) bromide, which another part is formed by New Amorphous oscillator.

This work is focused on interaction between hyaluronan (Hya) and amphiphilic molecules. Using fluorescent probes method were carried out screening of the interaction of various surfactants with Hya. For further examination was chosen cetyltrimethylammonium bromide (CTAB). Interactions in this system have also been studied using fluorescence correlation spectroscopy (FCS), and additionally were performed initial tests of the cytotoxicity of the system. As an alternative CTAB were also used hydrophobically modified amino acids. Results showed their self-aggregation, but their interactions with hylauronanem was not as strong as with CTAB. The interaction of gel systems Hya-CTAB have also been studied, and was found to contain a hydrophobic domain capable solubilize hydrophobic substance. Thermogravimetric have been established that are able to contain up to 98% wt. water and rheologically were characterized their mechanical properties. These are tunable due to molecular weight (MW) of the hyaluronate. With increasing value of MW increases mechanical strength of the gel and decreases its fluidity.

Les teneurs en pesticides mesurées dans les eaux de drainage agricole peuvent atteindre 10 µg/L voire 395 µg/L. En Lorraine, des Zones Tampons Végétalisées Agricoles (ZTVA) ont été installées en sortie de drains agricoles afin de limiter le transfert de ces eaux de drainage vers la rivière. L’objectif de ce travail était d’évaluer l’influence de l’hydraulique sur l’épuration des pesticides et métabolites en phases dissoute et particulaire des eaux de drainage, en discriminant les processus associés. Pour cela, une approche multi-échelle intégrant des expérimentations au laboratoire en batch et en bacs pilotes ainsi qu’un monitoring pluriannuel de deux ZTVA sur le terrain (un fossé et une mare) a été mise en place. Les expériences de traçages in-situ ont montré que quel que soit le débit, la ZTVA peut être divisée en différentes zones hydrauliques : un chenal principal et des zones isolées, qui se comportent différemment vis-à-vis de l’épuration. Les efficacités d’épuration dans les deux ZTVA varient de (i) -1176% à 96% pour les pesticides dissous, (ii) -20% à 3% pour les métabolites (chloroacétanilides) à l’état dissous, et (iii) -580% à 79% pour les pesticides sous forme particulaire. L’adsorption sur les sédiments permet l’épuration des pesticides à l’état dissous dont le coefficient d’adsorption (Koc) varie de 364 à 1424 L/g (entre 7 et 65% d’épuration), et est favorisé au sein des zones isolées. Cependant, ce processus est réversible et la désorption peut expliquer les efficacités négatives mesurées sur le terrain. Par ailleurs, les pesticides plus hydrophiles (Koc varie de 54 à 401 L/g) et les métabolites (Koc varie de 0 à 0.77 L/g) sont peu épurés (entre -20 et 8% d’épuration). Enfin, les pesticides entrant dans la ZTVA sous forme particulaire sont épurés via la sédimentation des matières en suspension, plus importante dans les zones isolées que le chenal principal. Ce processus est réversible, pouvant conduire à la resuspension des sédiments. Par ailleurs, les débits entrants vont fluctuer au cours de l’année, pouvant entrainer une variation de l’épuration des pesticides. En effet, les études en batch et en bacs pilotes ont permis de souligner l’influence de l’hydrodynamique (débits, etc) sur l’épuration des pesticides à l’état dissous. Ces ZTVA jouent donc un rôle de puits (adsorption, sédimentation) et de source (désorption, resuspension) vis-à-vis de certains pesticides à l’état dissous ou particulaire, en lien avec l’hydrodynamique de la ZTVA / Pesticides amounts measured in agricultural drained water can reach 10 µg/L up to 395 µg/L. In Lorraine, Constructed Wetlands (CW) were set up between drained fields and the river to limit pesticide release. The aim of this study was to evaluate the influence of hydraulic on the mitigation of pesticides and metabolites in both dissolved and particulate phases of drained water, by discriminating associated processes. To do so, a multi-scale approach was performed by integrating both laboratory experiments, such as batch and dynamic conditions in pilots, and a plurennial monitoring of two different ZTVA (ditch and pond). In-situ tracing experiments highlighted that the volume of CW was not homogeneous, independently of the flow rate. CW are divided in two hydraulic zones: a main channel and isolated areas. Moreover, these two zones behave differently regarding pesticides mitigation. Annual mitigation efficiency in both of the CW studied, vary between (i) -1176 % and 96 % for dissolved pesticides, (ii) -20 % and 3 % for dissolved metabolites (chloroacetanilides), and from (iii) -580 % to 79 % for particulate pesticides. Adsorption on sediments allows the mitigation of dissolved pesticides whose adsorption coefficient (Koc) varied from 364 to 1424 L/g (mitigation ranging from 7 to 65 %), and occurred mainly in isolated areas. However, this process is reversible and desorption can explain negative efficiency measured on the field. Additionally, hydrophilic pesticides (Koc between 54 and 401 L/g) and metabolites (Koc between 0 and 0.77 L/g) are few or not mitigated (mitigation ranging from -20 and 8 %). Finally, pesticides entering CW under particulate phase are mitigated through sedimentation of total suspended solids, higher in isolated areas than in main channel. This process is also reversible, leading to sediments resuspension. Otherwise, inlet flow rates vary throughout the year, which could allow a variation of pesticide mitigation. Indeed, batch and pilots studies highlighted the influence of hydrodynamic (flow rate, etc) on mitigation of dissolved pesticides. CW act as a sink (adsorption and sedimentation) and a source (desorption and resuspension) towards specific dissolved or particulate pesticides and related to hydrodynamic of CW

A new free radical chain process for the allylation of hydrocarbons and some other substrates utilizing substituted allyl bromides (R-H + C=C-C-Br -> R-C-C=C + HBr) has been developed. Good to excellent yields were observed in all cases. Kinetic chain measurements and competition experiments were performed in order to elucidate the mechanism of the reaction. Overall, the results are consistent with a free radical chain process with bromine atom as the chain carrier. Substitution effects on the reactivity of the allyl bromides (CH2=C(Z)CH2Br) and their influence on the overall reaction rate were studied by conducting several competition experiments. The relative rate constants for addition of benzyl radical to CH2=C(Z)CH2Br are: Z=CN(180), COOEt(110), Ph(65), H(1.0). The trend of electronegativity/reactivity of these reactions was very similar to that reported for addition of benzyl radical to substituted alkenes. Other than alkyl aromatics (PhCH3, PhCH(CH3)2), other substrates (i.e., 2- propanol, phenyl cyclopropane) were also tested for this allylation reaction. The magnitude and scope of these reactions, and their synthetic utility is discussed. / Ph. D.

No description available.

Macrophomina phaseolina (Mp) and Fusarium oxysporum f. sp. fragariae (Fof) are emerging soilborne pathogens causing crown rot and Fusarium wilt, respectively, in commercial strawberry production in California. Fungicides representing eight active ingredients from four different mode of action groups (FRAC groups 1, 3, 7 and 12) were evaluated for their efficacy against each pathogen in vitro and each disease in planta. Fungicide active ingredients were evaluated for their ability to inhibit mycelial growth of both pathogens in vitro. Half-strength potato dextrose agar was amended with six different concentrations (0.01, 0.1, 1.0, 5.0, 10, 50 µg a.i./ml) of seven fungicides in FRAC groups 3, 7 and 12. Concentrations that inhibited fungal growth by 75% (EC75) compared to unamended media were determined for two different isolates each of Mp and Fof and were used to determine fungicide rates for subsequent in planta studies. Tebuconazole strongly inhibited the mycelial growth of both pathogens (average EC75 for Mp was 2.4 ppm; average EC75 for Fof was 7.48 ppm), as did metconazole (average EC75 for Mp was2.53 ppm; average EC75 for Fof was 1.28 ppm). Fludioxonil strongly inhibited mycelial growth of Mp, but had no impact on the growth of Fof. Penthiopyrad, fluopyram, flutriafol, and flutolanil were less effective at inhibiting fungal growth of either fungus. Greenhouse in planta studies evaluated twenty-four fungicide treatments (eight fungicides at low, med and high rates) that were drench applied to infested potting media two days prior to planting of pathogen susceptible strawberry cultivars (San Andreas for Mp and Monterey for Fof) and again at day 21. Controls were a non-inoculated and an inoculated water-drench treatment. Buried inoculum was recovered at days 2 and 23 and plated on selective media for colony forming unit (CFU) quantification. Plant disease assessments were made each week for 11 weeks. An analysis of variance (ANOVA) of CFUs revealed no significant differences (p > 0.05) among treatments and when compared to the non-treated control for both Mp and Fof, but showed significant decreases (p < 0.05) in CFUs between weeks 1 and 3 for both Mp and Fof. An ANOVA for disease assessments in the form of area under the disease progress curve (AUDPC) showed significant decreases of disease severity in treatments with penthiopyrad only (low, medium and high rates) (p < 0.05). There were no significant differences (p > 0.05) in AUDPC among treatments and when compared to the non-inoculated and no-fungicide controls for Fof. The data indicates that these fungicides used alone are not effective against these pathogens in planta. A strawberry plant extract (germination stimulant) was assessed for its ability to stimulate germination of Mp microsclerotia in vitro and in planta. The germination stimulant was applied as a drench at six different concentrations (0, 10, 100, 1,000, 10,000 and 30,000 ppm) to soil containing filter disk packets of microsclerotia of Mp at day 0 and 14. Filter disk packets were retrieved three days after the drench and microsclerotia were observed microscopically for germination. Results showed that the number of germinating microsclerotia was significantly higher after the application of the germination stimulant compared to non-drench and 0 ppm controls (p < 0.001). An integrated container trial was also conducted using the germination stimulant at 10,000 ppm applied three days prior to a fungicide drench with tebuconazole or thiophanate-methyl to determine the effect of fungicides on the germinated microscleotia. The use of the germination stimulant with label rates of the fungicides lowered the number of germinated intact microsclerotia significantly (p < 0.001) especially after two drench applications. The use of the germination stimulant with fungicides could be investigated further as one method for controlling soilborne diseases of strawberry.

Tyrophagus putrescentiae, known as the ham mite, is the most difficult pest to control in the dry-cured ham industry. Food-grade propylene glycol coated nets have been studied as an alternative to conventional mite infestation treatments but were heavy and costly to ship. This study aimed to increase the ease of use of the coated nets via drying. Three drying treatments: oven dried for 7 min (OD7m), oven dried for 20 min (OD20m), and counter dried for 24 h (CD24h), were tested to determine the efficacy at controlling mites as well as the mechanical properties of the nets and sensory characteristics of ham wrapped in the treated nets. The OD7m and CD24h treatments were effective at controlling mite growth in a laboratory setting. The drying treatments did not affect the mechanical properties, or the sensory characteristics of the hams wrapped with the dried net treatments.

A interação entre fragmentos de bicamada (BF) de brometo de dioctadecildimetilamônio (DODAB) e um mononucleotídeo-modelo (deoxiadenosina monofosfato, dAMP) ou um oligodeoxinucleotídeo-modelo (5\'- AAAAAAAAAA-3\', poli(dA)) ou um oligodeoxinucleotídeo terapêutico (5\'- TTGACGTTCG -3\', CpG) foi investigada por turbidimetria, espalhamento de luz dinâmico, espectroscopia de dicroísmo circular e de fluorescência e calorimetria diferencial de varredura (DSC). Respostas imunológicas foram caracterizadas com ensaio de hipersensibilidade tardia por inchamento de coxim patelar de camundongo, dosagem de anticorpos IgG1 e IgG2a e de citocinas secretadas por células de linfonodo em cultura. Poli(dA), em contraste com dAMP, induziu fusão máxima de DODAB BF a partir da neutralização de cargas, quando houve obtenção de um tamanho máximo e um potencial-zeta igual a zero para os arranjos. Para [poli(dA)] maiores do que aquela correspondente à neutralização de cargas, houve recuperação da estabilidade coloidal com reversão do potencial-zeta e com obtenção de tamanhos que foram aproximadamente o dobro daqueles determinados inicialmente para DODAB BF. A proporção molar de neutralização poli(dA): DODAB foi 1:10 para DODAB BF e 1:20 para vesículas grandes (LV) de DODAB, de acordo com as estruturas de bicamada aberta e fechada dessas duas dispersões de bicamada de DODAB. A fusão de DODAB BF induzida por poli(dA) foi extensiva aumentando o grau de empacotamento das bicamadas formadas conforme inferido a partir dos termogramas de DSC. Em condições de equivalencia de cargas, nucleotídeo não causou fusão de DODAB BF, mostrando a importância do caráter de polieletrólito do poli(dA) para induzir fusão. O sal divalente Na2HPO4 causou fusão e aumentou o empacotamento da bicamada graças à blindagem eficiente de cargas. Reestabilização coloidal como aquela induzida por poli(dA) não ocorreu em presença de Na2HPO4, NaCl ou nucleotídeo. Para complexos DODAB BF/CpG em presença de ovalbumina (OVA) como antígenomodelo, a neutralização de cargas de DODAB BF/OVA por CpG reduziu a estabilidade coloidal, enquanto que supercompensação de cargas levou à reestabilização por repulsão eletrostática, como observado para a interação DODAB BF/poli(dA). Diferenças no tamanho e nas proporções de neutralização por CpG indicaram que os fragmentos são capazes de carregar mais moléculas de OVA do que de BSA. Na região de supercompensação de cargas com potenciais-zeta negativos, arranjos Al(OH)3/ OVA/ CpG são coloidalmente bem mais instáveis que DODAB BF/ OVA ou DODAB BF / OVA/ CpG. O complexo negativamente carregado DODAB (0,1 mM) / OVA (0,1mg/mL)/ CpG (0,020 mM) potencializou a resposta Th1 obtida com DODAB (0,1 mM)/ OVA (0,1 mg/mL). Houve um aumento de 25 % no inchamento do coxim patelar, de 36 % na produção de IFN-&#947;, de 60 % de IL-12 e produção sustentada de IgG2a ao longo de 35 dias pós-imunização, todos indícios fortes de potencialização da resposta Th1 por CpG. Arranjos negativamente carregados de oligonucleotídeos em fragmentos de bicamada de DODAB possuem excelente potencial para terapias baseadas em oligonucleotídeos e para produção de vacinas para diferentes antígenos de interesse. / The interaction between bilayer fragments (BF) of dioctadecyldimethylammonium bromide (DODAB) and a model nucleotide (deoxyadenosine monophosphate, dAMP) or a model oligodeoxynucleotide (5\'- AAAAAAAAAA-3\', poly(dA)) or a therapeutic oligodeoxynucleotide (5\'- TTGACGTTCG -3\', CpG) was investigated by means of turbidimetry, dynamic light scattering, circular dichroism and fluorescence spectroscopies and differential scanning calorimetry. Immune responses were characterized using footpad swelling delayed type hipersensitivity assay and antibody and cytokine measurements. In contrast to dAMP, poly(dA) induced maximal DODAB BF fusion from charge neutralization, where assemblies presented maximal size and zero zeta-potential. Above charge neutralization colloid stability was recovered with negative zeta-potentials and sizes that were about the double of those initially determined for DODAB BF. The poly(dA):DODAB molar ratio for neutralization was 1:10 for DODAB BF and 1:20 for DODAB LV, in agreement with the open and closed bilayer structures of these two DODAB bilayer dispersions. The poly(dA)-induced DODAB BF fusion was extensive and increased the packing of the formed bilayers, as inferred from DSC thermograms. In conditions of charge equivalence, nucleotide did not cause DODAB BF fusion, highlighting the importance of poly(dA)\'s polyelectrolyte character to induce fusion. Divalent Na2HPO4 salt caused fusion and increased bilayer packing due to efficient BF charge shielding. Colloid restabilization as induced by poly(dA) was not observed in presence of Na2HPO4, NaCl and nucleotide. For DODAB BF/CpG complexes in presence of the ovalbumin (OVA) model antigen, the charge neutralization of DODAB BF/OVA by CpG reduced colloid stability, while charge overcompensation led to restabilization due to electrostatic repulsion, as observed for DODAB BF/poly(dA) interaction. Differences in size and neutralization proportions by CpG indicate that BF are able to load more OVA than BSA molecules. In the charge overcompensation region with negative zeta-potentials, Al(OH)3/OVA/CpG assemblies are colloidally less stable than DODAB BF/OVA or DODAB BF/OVA/CpG. The negatively charged DODAB (0.1mM)/OVA (0.1mg/ml)/CpG (0.020mM) assembly enhanced the Th1 response obtained with DODAB (0.1mM)/OVA (0.1mg/ml). There was a 25% increase in footpad sweeling, a 36% and 60% increase in the production of IFN-&#947; and IL-12 and sustained IgG2a production for the 35-day period after immunization, all indicative of strong Th1 response enhancement by CpG. Negatively charged assemblies of oligonucleotides in DODAB bilayer fragments have excellent potential in oligonucleotidebased therapies and in vaccine production for different antigens of interest.

A bactéria Neisseria meningitidis é um diplococo Gram-negativo. Dentre os sorogrupos de N. meningitidis, o sorogrupo B é um dos principais causadores da doença meningocócica invasiva (DMI), de ocorrência mundial. Recém-nascidos e crianças são especialmente susceptíveis a este tipo de infecção, uma vez que os seus sistemas imunitários ainda estão em desenvolvimento, assim mais estudos sobre a utilização da imunização materna para a proteção contra esta doença, são necessários. O objetivo desse estudo foi avaliar o potencial imunogênico dos antígenos de membrana externa de N. meningitidis sorogrupo B em camundongos Swiss quanto ao efeito da imunização passiva na prole, além de analisar o efeito de diferentes adjuvantes na produção de anticorpos e transferencia materno-fetal destes. O hidróxido de alumínio (HA) e fragmentos de bicamada de brometo de dioctadecildimetilamônio (DODAB-BF) foram utilizados como adjuvantes junto às vesículas de membrana externa (OMVs) para a imunização de camundongos adultos fêmeas, o que resultou em um aumento dos títulos de anticorpos do isótipo IgG quando comparado a imunização apenas com o antígeno, tanto pela via de imunização subcutânea com booster intramuscular (SC/IM), quanto pela via intranasal com booster subcutâneo (IN/SC). Esses anticorpos foram transferidos para a prole, que apresentou títulos de anticorpos significantes até o período no qual os camundongos apresentavam cinco semanas de vida. A imunização com OMVs + DODAB-BF foi capaz de gerar o reconhecimento específico de um maior número de antígenos que OMVs + HA, nos camundongos adultos fêmeas imunizados pela via SC/IM. A imunização com OMVs + DODAB-BF pela via SC/IM também resultou em anticorpos na prole que foram capazes de reconhecer antígenos proteicos da cepa homóloga e de cepas heterólogas, o que não ocorre quando essa imunização é realizada pela via IN/ SC. Apesar da presença de títulos de anticorpos na prole, estes irão apresentar funcionalidade diferente em comparação aos anticorpos da prole de mães imunizadas pela via SC/IM, sugerindo que a via SC/IM é melhor para a imunização materna com OMVs + DODAB-BF. / The Neisseria meningitidis bacterium is a Gram-negative diplococcus. Among the serogroups of N. meningitidis, serogroup B is one of the main causes of invasive meningococcal disease (IMD), worldwide occurrence. Newborns and children are particularly susceptible to this type of infection, since their immune systems are still developing, so further studies about the use of the maternal immunization to protect against this disease, are needed. The aim of this study was to evaluate the potential immunogenic antigens from outer membrane of N. meningitidis serogroup B in Swiss mice as to the effect of passive immunization in the offspring, in addition to analyze the effect of different adjuvants in the production of antibodies and maternal-fetal transfer of these. The aluminium hydroxide (HA) and bilayer fragments from dioctadecyldimethylammonium bromide (DODAB-BF) were used as adjuvants with the outer membrane vesicles (OMVs) for immunization of adult female mice, which resulted in an increase of the antibodies titers of IgG isotype when compared to immunization with only the antigen, either by subcutaneous route of immunization with intramuscular booster (SC/IM), as by the intranasal route with subcutaneous booster (IN/SC). These antibodies were transferred to the offspring, which presented significant antibodies titers to the period in which the mice had five weeks of live. Immunization with OMVs + DODAB-BF was able to generate the specific recognition of a greater number of antigens than OMVs + HA, in adult female mice immunized by SC/IM route. Immunization with OMVs + DODAB-BF SC/IM route also resulted in antibodies in offspring that were able to recognize protein antigens of the homologous strain and heterologous strains, which does not occur when this immunization is carried out by IN/SC route. Despite the presence of antibodies in the offspring, they will present different functionality compared to antibodies of the offspring of mothers immunized by SC/IM route, suggesting that the SC/IM route is better for maternal immunization with OMVs + DODAB-BF.