Submitted by Maria Suzana Diniz (msuzanad@hotmail.com) on 2015-10-14T14:54:42Z No. of bitstreams: 1 arquivototal.pdf: 2900404 bytes, checksum: 1ee5854e28bd882478910deb4dcb5943 (MD5) / Made available in DSpace on 2015-10-14T14:54:42Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 2900404 bytes, checksum: 1ee5854e28bd882478910deb4dcb5943 (MD5) Previous issue date: 2015-02-24 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Workers chronically exposed to a variety of organic solvents may suffer from changes in color vision and contrast sensitivity (CS). However, few studies have investigated whether there are sex-related differences in these changes, one of the factors that can change the toxicokinetics of solvents. Hence, the aim of this study was to determine whether there would be differences between women and men exposed in terms of their chromatic and achromatic visual psychophysical responses. A total of 44 individuals, Control Group total (CGt; n = 22) and Study Group total (SGt; n = 22) participated in the experiment, subdivided into the following groups: Study Group men (SGm): 11 men exposed to solvents (Age, M = 30.18, SD = 6.48; Education level, M = 9.73, SD = 2.10; Work duration, M = 6.53, SD = 4.38); Study Group women (SGw): 11 women exposed to solvents (Age, M = 26.91, SD = 5.86; Education level, M = 10, 36, SD = 0.92; Work duration, M = 4.70, SD = 3.53); Control Group men (CGm): 11 unexposed men (Age, M = 26.73, SD = 6.5; Education level, M = 9.73; SD = 1.8); Control Group women (CGm): 11 unexposed women (Age, M = 26.55, SD = 6.5; Education level, M = 10.45; SD = 1.51). The project was approved by the Ethics Committee of the Health Sciences Center (SCC) at the Federal University of Paraíba (UFPB), with CAAE registry number 21350113.9.0000.5188. Initially the participants underwent a screening step, with the following inclusion criteria, among others: a 20/20 or corrected visual acuity (evaluated via optotypes and Rasquin testing) and no dyschromatopsia (evaluated using Ishirara Test). Assessment of color perception was performed using the D15 desaturated Lanthony test (D15d) and the Cambridge Colour Test (CCT). The evaluation was performed by CS stimulation using sinusoidal gratings with a vertical spatial frequency of 0.2, 0.5, 1.0, 2.0, 5.0, 10, and 16 cycles per degree (cpd) of visual angle. Furthermore, an assessment of body composition from an examination of bioimpedance. The data were analyzed using the SPSS software package, version 21. First, the overall results between the SGt group (n = 22) and CGt group (n = 22) were compared, and were subsequently compared by sex (n = 11). The results showed that the study group (SGt) (Mdn = 1.18; M = 1.31, SD = 0.32) had a significantly higher ICC (U = 128, p = 0.01) than the CGt (Mdn = 1.09; M = 1.10, SD = 0.26), while there were no significant differences between solvent-exposed men and women (U = 51.0, p = 0.53). In CCT testing (Trivector Protocol), the SGt had a length corresponding to the vector protan axis (Mdn = 50.00; M = 54.00, SD = 16.42), and was significantly higher (U = 133.50, p = 0, 01) than the combined CGt group (Mdn = 40.00; M = 42.59, SD = 16.42), while according to the ellipse protocol, the SGt (Mdn = 981.15; M = 8086.81 ; SD = 22787.81) had a significantly higher ellipse area in A3 (U = 158.00, p = 0.04) compared to the CGt (Mdn = 657.30; M = 781.75, SD = 528.68), but men and women showed no significant differences in both CCT protocols (p > 0,05). The results of the CS showed that the SGt had lower CS in the following frequencies: 0.2 (U = 116,500, p = 0.003); 0.5 (U = 117.00, p = 0.003); 5.0 (U = 149.50, p = 0.03) and 10 cpd (U = 150.00, p = 0.03) compared to the CGt. The SGm (U = 25.0, p = 0.02) had significantly higher CS than SGm at the 0.5 cpd frequency value. The correlational analyses showed that among SGw, the diameter values of circles equivalent to the A1 and A2 ellipse areas retained a significant correlation with MCM: ρ = -0.68; p = 0.02 and ρ = -0.83; p = 0.01, respectively. Among SGw, the diameter value of the circle equivalent to the A2 area was negatively correlated with fat mass: ρ = -0.67; p = 0.02, in other words a greater amount of fatty tissue was correlated with a lower error trend in the red-green opponency axis, in addition, the diameter value of the circle equivalent to the A3 area had a positive correlation with MCM: ρ = 0.61; p = 0.04, i.e. a greater amount of MCM was correlated with a greater tendency to error in the color opponency axis. In short, the data on color vision and the SC obtained by solvent-exposed women and men found no strong evidence of possible differences between the sexes. However, the associations of psychophysiological measurements with the body measurements seem to indicate that fat can act as a protective factor of the organism against the effects of solvents, since fatty tissues may retain a proportion of solvents. In this regard, women could be less affected by solvents by having, on average, a larger proportion of adipose tissue than men. / Trabalhadores expostos de forma crônica à mistura de solventes orgânicos podem sofrer alterações na visão de cores e na sensibilidade ao contraste (SC). Entretanto, poucos estudos investigaram se há diferenças entre os sexos, um dos fatores que podem alterar a toxicocinética dos solventes. Diante disto, o objetivo do presente estudo foi verificar se haveria diferença entre mulheres e homens expostos quanto as respostas psicofísicas visuais cromáticas e acromáticas. Participaram 44 pessoas, Grupo de Estudo total (GEt; n = 22) e Grupo Controle total (GCt; n = 22) que formaram os seguintes grupos: Grupo de Estudo Homens (GEh): 11 homens expostos (Idade M = 30,18; DP = 6,48; Escolaridade M = 9,73; DP = 2,10; Tempo de serviço M = 6,53; DP = 4,38); Grupo de Estudo Mulheres (GEh): 11 mulheres expostas (Idade M = 26,91; DP = 5,86; Escolaridade M = 10, 36; DP = 0,92; Tempo de serviço M = 4,70; DP = 3,53); Grupo Controle Homens (GCh): 11 homens não expostos (Idade M = 26,73; DP = 6,5; Escolaridade M = 9,73; DP = 1,8); Grupo Controle Mulheres (GCm): 11 mulheres não expostas (Idade M = 26,55; DP = 6,5; Escolaridade M = 10,45; DP = 1,51). O projeto foi aprovado pelo Comitê de Ética do Centro de Ciências da Saúde (CCS) da Universidade Federal da Paraíba (UFPB), com número de CAAE: 21350113.9.0000.5188. Inicialmente os participantes realizaram uma de triagem, permanecendo aqueles que, entre outros critérios, apresentaram acuidade visual 20/20 ou corrigida (Optotipos E de Rasquin) e ausência de discromatopsias congênitas (Teste de Ishirara). A avaliação da percepção cromática foi realizada por meio dos testes D15 Dessaturado de Lanthony (D15d) e Cambridge Colour Test (CCT). A avaliação da SC foi realizada com estímulos de grades senoidais verticais de frequências espaciais de 0,2; 0,5; 1,0; 2,0; 5,0; 10 e 16 cpg de ângulo visual. Ainda foi realizada uma avaliação da composição corporal a partir de um exame de biompedância. Os dados foram analisados por meio do software SPSS, versão 21. Primeiramente, foram comparados os resultados entre o GEt (n = 22) e o GCt (n = 22), em seguida os resultados foram comparados por sexo (n = 11). Os resultados mostraram que o GEt apresentou ICC (Mdn = 1,18; M = 1,31; DP = 0,32) significativamente maior (U = 128; p = 0,01) ao GC (Mdn = 1,09; M = 1,10; DP = 0,26), ao passo que entre mulheres e homens expostos não houve diferenças (U = 51,0; p = 0,53). Com relação ao CCT, Protocolo Trivector, o GEt apresentou comprimento correspondente ao vetor do eixo protan (Mdn = 50,00; M = 54,00; DP = 16,42) significativamente maior (U = 133,50; p = 0,01) que o GC (Mdn = 40,00; M = 42,59; DP = 16,42), já no Protocolo Elipse, o GEt obteve área da elipse A3 (Mdn = 981,15; M = 8086,81; DP = 22787,81) significativamente maior (U = 158,00; p = 0,04) em relação ao GCt (Mdn = 657,30; M = 781,75; DP = 528,68), mas homens e mulheres não apresentaram diferenças em ambos os protocolos do CCT (p > 0,05).. Os resultados da SC mostraram que o GEt apresentou SC menor nas frequências: 0,2 (U = 116,50; p = 0,003); 0,5 (U = 117,00; p = 0,003); 5,0 (U = 149,50; p = 0,03) e 10 cpg (U = 150,00; p = 0,03) comparado ao GCt. O GEm obtive SC significativamente maior (U = 26,0; p 0,02) que o GEh na frequência 0,5 cpg. As análises correlacionais evidenciaram que entre o GEh, os valores dos diâmetros dos círculos equivalentes as áreas das elipses A1 e A2 mantiveram correlação com a MCM: = -0,68; p = 0,02 e = -0,83; p = 0,01, respectivamente. Já entre o GEm o valor do diâmetro do círculo equivalente a área A2 apresentou correlação negativa com a massa de gordura: = -0,67; p = 0,02, ou seja quanto mais gordura, menor tendência de erro no eixo de oponência de cor vermelho-verde, e ainda o valor do diâmetro do círculo equivalente a área A3 obteve correlação positiva com a MCM: = 0,61; p = 0,04, isto é quanto maior a quantidade de MCM, maior tendência de erro no eixo de oponência de cor. Em suma, os dados relativos à visão de cores e a SC obtidos por mulheres e homens expostos não encontraram fortes evidências de possíveis diferenças entre os sexos. Entretanto, as associações das medidas psicofísicas com as medidas corporais parecem indicar que a gordura pode atuar como um fator de proteção do organismo contra os efeitos dos solventes, já que tecidos gordurosos podem reter produto. Nesta perspectiva, as mulheres poderiam ser menos afetadas por apresentarem quantidade maior de tecido adiposo.

Technologies that facilitate reusing and recycling printed textile products will contribute to achieving a circular textile industry. This project was done in collaboration with Vividye, a company developing a technology to create removable textile prints to be able to extend the lifespan of screen-printed textile products without affecting their quality. The technology involves several steps, including re-formulating printing paste and using a treatment to remove the print. This particular treatment consists of the use of different organic solvents. The aim of this project was to evaluate the effect of four organic solvent treatments, which are of interest to the company, on the physical and sensorial properties of conventional cotton (CO) and polyester (PET) knitted fabrics. Three cycles of the treatment were evaluated. Significant changes in yarn and fabric properties, such as tension and thickness, were found after the treatment, also for fabric sensorial properties, such as stiffness, softness, and smoothness. The behavior was different for each type of material which can be attributed to the affinity between the polymer and the solvent and the polymer, yarn, and fabric structure that facilitates the swelling. The properties assessed within this project can be related to the fabric's quality and feel. Therefore, it can be an essential factor in the user's preferences or influence the material's printability.

Tissue Engineering is a scientific discipline that aims to regenerate tissues and organs that are diseased, lost or congenitally absent. It encompasses the use of suitable synthetic equivalents of native extracellular matrix that may or may not be supplemented with cells or relevant growth factors. Such scaffolds are designed to reside at the site of implantation for a variable period of time during which they induce the regeneration of native tissue. During this time, they also provide a template for new cells to attach, infiltrate, differentiate into appropriate phenotype and eventually restore function of the concerned tissue. Among the factors that affect the outcome are the composition of scaffold, methods of fabrication, bulk properties of the scaffold and topography and architecture at the cellular level. Bone is unique in the body in that it is one of the few tissues capable of complete regeneration even in adults, as seen during fracture healing. However, certain conditions (non-union of fractures, congenital and acquired bone deficiencies) exist in which the regenerative capacities of bone are exceeded and appropriate intervention becomes necessary. Current treatment options include autologous bone grafts harvested from iliac crest or de-cellularized allografts or synthetic substitutes made from metals, ceramics and polymers. However these options have serious limitations: while autografts are limited in supply, necessitate second surgery and show inadequate vascularization, allografts can transmit viral infections. Metals, ceramics and polymers are in essence structural replacements without performing any biological function. Other problems associated with these synthetic materials include adverse immune reactions, corrosion, stress-shielding and secondary fractures due to inadequate osseo-integration. Bone tissue engineering is a specialized field of research that provides an alternative strategy to repair bone defects by exploiting the advances in engineering and better understanding of bone biology. Scaffold-based tissue engineering approach is a promising field that involves implantation of a biomaterial that is specifically matched in terms of biological and material properties to the tissue it replaces. This study explores the feasibility of using electrospinning as a potential fabrication strategy for bone tissue engineering applications, more specifically intended for cleft palate repair. This model represents a congenital deformity that affects both hard and soft tissues and presents unique challenges and opportunities. Among the challenges are: the need for the implant allow growth of the most complex areas of the facial skeleton, integrate and grow with the patient through adolescence, the ability of the implant to not interfere with vital functions including breathing and feeding. Further the implant should provide a flexible matrix that can effectively support erupting teeth. In spite of these extreme demands, maxilla is a non load-bearing membranous bone, a favorable consideration from materials engineering perspective. The present study is organized into three independent sections. The first section investigates developing strategies intended to improve the material properties of electrospun bone scaffold. Bone is composed of a high volume fraction (50%) of inorganic hydroxyapatite nanocrystals that is closely associated with collagen. The dispersal of brittle mineral is critical in not only strengthening the bone in compression but also contributes to the osteoconductivity of the matrix. Since loading of mineral in a bone scaffold is a serious limitation, we attempted to achieve improved loading of bone mineral by dual mineralization approach. We first incorporated nanocrystalline hydroxyapatite (nHA) directly into the scaffold by adding it to the electrospinning polymer solution. The second step involves inducing biomimetic mineralization of electrospun scaffolds by incubating them in simulated body fluid (SBF) for 2 weeks. The hypothesis was that the nanocrystalline hydroxyapatite seeded during electrospinning would act as sites for nucleation and further crystal growth when incubated in solution supersaturated with respect to calcium and phosphate ions. We tested this approach in two synthetic, biocompatible polymers-polydioxanone and poly (lactide: glycolide) and four formulations of SBF with differential loading of nHA (0-50% by wt. of polymer). A modified Alizarin Red S (ARS) staining that specifically binds to calcium was developed that allowed us to quantify the mineral content of 3D scaffold with great accuracy. Results indicated a unique combination of factors: PDO scaffolds containing 50% nHA incubated in 1x revised-SBF incubated under static conditions gave maximum mineralization over a period of two weeks. We then sought to exploit these findings to engineer a stiffer scaffold by stacking multiple layers together and cold welding them under high pressure. Electrospun scaffolds (1, 2 or 4 layered stacks) were either compressed before or after mineralizing treatment with SBF. After two weeks, scaffolds were analyzed for total mineral content and stiffness by uniaxial tensile testing. Results indicated while compression of multiple layers significantly increases the stiffness of scaffolds, it also had lower levels of mineralization partly due to increased density of fibers and loss of surface area due to fiber welding. However this can be offset to a reasonable degree by increasing the number of stacks and hence this strategy can be successfully adopted to improve the mechanical properties of electrospun scaffolds. The second section introduces a novel infrared imaging technique to quantify and characterize the biological activity of biomaterials, based on cell adhesion. Cells attach to the surface by the formation of focal contacts where multiple proteins including vinculin and talin assemble to signal critical processes like cell survival, migration, proliferation and differentiation. After allowing MG-63 osteoblasts to adhere to 2D biomaterial surface coated with extracellular matrix proteins (collagen, gelatin, fibronectin) cells were fixed and probed with antibodies for vinculin and talin. Secondary antibodies, tagged with infrared-sensitive fluorescent dyes, were used to quantify the molecules of interest. In addition, the kinetics of focal contact formation in these different substrates was followed. Successful quantification of focal contacts were made and further research revealed phosphorylation of vinculin at pY-822 as one potential mechanism for recruitment of vinculin to focal contacts. Hence it could represent a subset of vinculin and might serve as a specific molecular marker for focal contacts. As an extension, we evaluated the possibility of using such an assay to quantify 3D electrospun tissue engineering scaffolds. We fabricated scaffolds of graded biological activity by electrospinning blends of polydioxanone and collagen in different ratios. Vinculin and talin expressed by MG-63 cultured on these scaffolds for 24 hours were quantified in a similar manner. Results indicate that while talin does not show a significant difference in expression among different scaffolds, vinculin showed a positive correlation with increasing biological activity of scaffolds. In conclusion, we have identified vinculin as a reliable marker of focal contacts in 3D scaffolds while phosphovinculin (pY-822) was more specific to focal contacts in coated 2D substrates. In both instances, infrared imaging proved to be reliable in study of focal contacts. The third section aims to make the bone scaffolds osteoinductive- a property of a material to induce new bone formation even when implanted in subcutaneous and intramuscular heterotopic sites. Bone morphogenetic proteins (BMP) are potent cytokines that can induce migration, proliferation and differentiation of stem cells along osteoblastic lineage. The therapeutic efficacy of BMPs in the treatment of severe bone defects has been identified and is currently FDA approved for specific orthopedic applications. BMPs are clinically administered in a buffer form that not only makes the treatment expensive but less effective. Suitable delivery systems for BMP delivery have been an intense area of investigation. We rationalized electrospinning as a strategy to incorporate BMP within the scaffold and that would enable controlled release when implanted. One of the drawbacks of using electrospinning to deliver bioactive molecules is the potential denaturing effect and eventual loss of activity of BMPs. The final section of this dissertation tries to develop sensitive and relevant assays that could answer intriguing questions about solvent-protein interaction. We chose to use the BMP-2/7 heterodimer as the osteoinductive molecule of choice because of its superior potency compared to homodimer counterparts. We characterized the detection and quantification of BMP-2/7 using a slot blot technique. Further, we used a novel cell line (C2C12 BRA) to test the retention of activity of BMP-2/7 that has been exposed to organic solvents. Results indicate significant loss of activity when BMPs are exposed to organic solvents but complete recovery was possible by diluting the solvent with an aqueous buffer.

Thesis (M. Tech. Chemistry, Dept. of Chemistry, Faculty of Applied and Computer Sciences)--Vaal University of Technology, 2010. / Membrane separation processes offer a promising alternative to energy-intensive separation processes such as distillation and solvent extraction. NF and RO are among the most investigated membrane processes with a potential use in the chemical industry. Carbon-carbon coupling reactions feature in the top ten most used reactions in the chemical industry. These reactions often use homogeneous palladium, nickel and other precious catalysts which are often difficult to separate from reaction products. This leads to potential product contamination and loss of active catalysts. This not only poses a threat to the environment but is also costly to the chemical industry. The purpose of this study was to investigate the efficiency of the recovery of the metal catalysts by selected membrane processes. Four commercial polymeric NF and RO membranes (NF90, NF270, BW30 and XLE) were selected for the study. Palladium catalysts commonly used in Heck and Suzuki coupling reactions were selected. These are Pd(OAc)2, Pd(OAc)2(PPh3)2, PdCl2 and Pd(PPh3)2Cl2. A range of organic solvents were also selected for the study. All the membranes were characterized for pure water permeability, pure solvent permeability, swelling, surface morphology and chemical structure. The chemical and catalytic properties of the catalysts were determined. Catalytic activity was investigated by performing coupling reactions. These catalysts generally performed well in the Heck coupling reaction with sufficient yields realized. The catalysts showed poor activities in the Suzuki and Sonogashira coupling reactions. These coupling reaction systems were affected by rapid palladium black formation. vi Catalyst retention studies showed the influence of membrane-solute interactions such as steric hindrance and size exclusion. The larger catalyst, Pd(OAc)2(PPh3)2 was rejected better by all the membranes irrespective of the solvent used. The smaller catalyst, Pd(OAc)2 was the most poorly rejected catalyst. This catalyst showed signs of instability in the selected solvents. An interesting finding from this study is that of higher rejections in water compared to other solvents for a particular catalyst. In this regard, the influence of solventsolute effects was evident. Generally, higher rejections were observed in solvents with higher polarity. This has been explained by the concept of solvation. It has been shown that solvents with different polarity solvate solutes differently, therefore leading to a different effective solute diameter in each solvent. Catalyst separation using NF90 membrane was attempted for the Heck coupling reaction system. The reaction-separation procedure was repeated for two filtration cycles with rapid activity decline evident. This was regarded as very poor showing of the catalyst separation efficiency of the membrane. Other authors in similar studies using SRNF membranes have reported reaction-separation processes of up to seven cycles. This observation shows the inferiority of polymeric membranes in organic solvent applications such as catalyst separation.

L’objectif de cette thèse de doctorat est le développement d’une nouvelle méthode théorique basée sur la simulation des équilibres liquide-gaz par simulations de dynamique moléculaire. Cette nouvelle m´méthode prédit les propriétés thermodynamiques telles que l’activité des solvants et les coefficients d’activité des solutés en phases aqueuses et organiques impliquées dans les systèmes d’extraction liquide-liquide. Ces propriétés thermodynamiques sont nécessaires pour les approches de modélisation thermodynamique mésoscopique permettant d’estimer l’efficacité et la s´électivité d’un système d’extraction par solvant jusqu’au une échelle industrielle. Les propriétés thermodynamiques et structurales des solutions électrolytiques aqueuses et des phases organiques, y compris les agrégats résultant des molécules d’extraction des amphiphiles, sont en bon accord avec les données expérimentales et théoriques disponibles. L’approche de dynamique moléculaire de l’équilibre osmotique fournit un nouvel outil puissant permettant d’accéder aux données thermodynamiques. / The aim of this PhD thesis is the development of a new theoretical method based on the simulation of vapor-liquid equilibria by means of molecular dynamics (MD) simulation. This new method predicts thermodynamic properties such as solvent activities and solute activity coefficients of aqueous and organic phases used in liquid-liquid extraction systems. These thermodynamic properties are required for mesoscopic thermodynamic modeling approaches estimating the efficiency and selectivity of a given solvent extraction system up to an industrial scale. Thermodynamic and structural properties of aqueous electrolyte solutions and organic solvent phase including aggregates resulting from amphiphilic extractant molecules are reproduced in very good agreement with previously available experimental and theoretical data. The osmotic equilibrium MD approach provides a new and powerful tool for accessing thermodynamic data

L’objectif général de ce travail était d’étudier la relation entre exposition professionnelle maternelle aux solvants organiques et malformations congénitales.Ce projet s’est appuyé sur les données de la cohorte PELAGIE. Il s’agit d’une cohorte mère enfant avec inclusion de 3 421 femmes en début de grossesse en population générale en Bretagne. L’exposition aux solvants était définie par différentes méthodes (expositions déclarées, matrices emplois-expositions, dosages urinaires de métabolites de solvants chlorés et d’éthers de glycol).Nous avons mis en évidence une relation entre l’exposition aux solvants mesurée par des méthodes indirectes et les malformations congénitales. Puis, pour un échantillon aléatoire de451 femmes, nous avons étudié les déterminants de la détection urinaire des métabolites de solvants. Enfin, dans le cadre d’une étude cas-témoins dans la cohorte, la relation entre métabolites urinaires de solvants et malformations congénitales a été étudiée. / The aim of this project was to study the relation between maternal occupational exposure to solvents and congenital malformations.This project used data from the PELAGIE study. This is a mother child cohort which had included 3 421 women from the general population at the beginning of their pregnancy in Britany. Occupational exposure to solvents was assessed by different methods (self-report, job exposure matrix, and urinary determination of glycol ethers and chlorinated solvents metabolites).We have shown an association between solvent exposure using indirect method of assessment and congenital malformations. Using a randomized sample of 451 women, we have studied the occupational and non occupational determinants of urinary detection of glycol ethers and chlorinated solvents metabolites. Finally, we have studied in a nested case-control study, the relation between urinary solvent metabolites and congenital malformations.

Different multiple-injection methodologies and the partial filling technique (PFT) have been utilized for separation of pharmaceuticals by capillary elec-trophoresis. In multiple-injection capillary zone electrophoresis (MICZE), the samples and all standards, used for construction of the calibration curve, are analyzed within a single run. Four different modes of MICZE have been described by means of equations, which were experimentally verified. The developed equations facilitate the transfer from conventional single-injection CZE to one or more of these MICZE-modes, depending on the selectivity between the analyte and the injection marker. The applicability of two of these modes was then demonstrated by quantification of buserelin and salbutamol, re-spectively in commercially available pharmaceutical products. The content of buserelin in an injection solution was determined to 0.94 mg/ml, which only deviated slightly from the declared concentration (1 mg/ml). An alter-native mode of MICZE, offering a higher number of sequential sample injec-tions, was then utilized for single-run determination of salbutamol in 15 tab-lets, with a labelled content of 8 mg. The average content of the tablets was determined to 7.8 mg, with an intra-tablet variation of 3 % or less. Moreover, UV- and mass-spectrometric detection of enantiomeric amines, resolved by non-aqueous capillary electrophoresis (NACE), was demon-strated. Separation of enantiomeric amines was achieved using the chiral selector (-)-2,3:4,6-di-O-isopropylidene-2-keto-L-gulonic acid, (-)-DIKGA. Introduction of the non-volatile (-)-DIKGA into the mass-spectrometer was avoided by using the PFT, where the capillary is only partially filled with electrolyte containing the chiral selector.

Made available in DSpace on 2015-05-14T13:16:23Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 3324327 bytes, checksum: b85304a7fe276b9b7697e2cdf5a23471 (MD5) Previous issue date: 2013-12-06 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / This study aimed at verifying exposure levels for gasoline and ethanol vapors and their psychophysical, neurocognitive, and physiological consequences in a sample of Brazilian pump attendants. Gas chromatography and microclimate sensing were used to passive and active monitoring of environmental levels of vapors. The psychophysical evaluation comprised the chromatic tests Lanthony D15-d and Cambridge Color Test 2.0, the Contrast Sensitivity Function using vertical sinusoidal gratings and Metropsis at the frequencies 0.2, 0.5, 1.0, 2.0, 5.0, 10.0, and 16.0 cpd, and eye-tracking at 250 Hz. Except by the D15-d test, all vision tests were performed with the dominant eye. The neurocognitive evaluation included the Trial Making Tests (A and B) and the Rey's Complex Figure Test. After applying exclusion criteria, the physiological evaluation was carried out in 16 attendants, who had a blood test to assess hepatic-biliary functions by the following markers: Alanine Aminotransferase (ALT), Aspartate Aminotransferase (AST), Direct Bilirubin (DB), Total Bilirubin (TB), and Gamma-glutamyl transpeptidase (GAMMA GT). The screening phase also included a questionnaire of Psychological and Neurophysiological Symptoms (PNS), a sociodemographic questionnaire, the Ishihara and the Rasquin 'E' tests. Thirty-eight pump attendants (Exposed Group) were selected, all males, with mean age of 32.66 years (SD = 1.30) and average schooling of 9.68 years (SD = 0.34). Thirty-eight volunteers (Control Group) were selected, all males, with mean age of 30.0 years (SD = 1.54), average schooling of 9.84 years (SD = 0.34), without reporting exposure to solvents and considered healthy following the inclusion criteria. The groups did not differ in age (p = .224) or schooling (p = .52), and all participants had normal or corrected-to-normal visual acuity 20/20. The Mann-Whitney test showed significant differences between scores in the Index of Color Confusion of the D15-d (p < .01, with losses in the tritan axis 75%), the Area of ellipses (protan, deutran, and tritan, all at p < .05), the frequencies 5, 10, and 16 cpd (p < .01), the Trail Making A (p < .01) and B (p < .05), the copy and memory of the Rey's complex figure (both at p < .01), and the number of saccades and trajectory time in the visual labyrinth (both at p < .01) as measure by the eye-tracker. The physiological evaluation showed changes in the values of DB (100 % of the pump attendants) and TB (62,5 %). Two attendants had combined changes in hepatic enzymes and biliburin. The Spearman correlation showed a significant association between the time of service and the areas protan (ρ = .46, p < .01) and deutan (ρ = .64, p < .01), the spatial frequency 5 cpd (ρ = .36, p < .05), and the Trail Making A (ρ = .40, p < .05) and B (ρ = .37, p < .05). The weight showed a tendency to attenuate the visual deficits, having a negative correlation with the area deutan (ρ = - .45, p < .01) and a positive one with contrast sensitivity at 0.20 cpd (ρ = .37, p < .05). Correlations were also found between DB and the time to perform the eye-tracker task (ρ = .58, p < .05) and the GGT and complaints of psychoneurovegetative instability (ρ = .57, p < .05). The Kruskal Wallis, and Mann-Whitney as a post-hoc test with Bonferroni's correction, showed that from 8 years of exposure there are consequences to color vision (Protan and Deutan) and for neurocognitive processes related to attention (Trail Making). The questionnaire PNS showed that 52.6% of pump attendants had symptoms of neuropsychological aggressions. Furthermore, there was a convergence between memory and attention complaints, with lower scores in the memory for the Rey's complex figure (ρ = - .34, p < .05). This study brings additional and new evidences for the consequences on color vision and contrast sensitivity, shows a potential occupational etiology in hepatic-biliary changes, presents neurocognitive xviii deficits in Brazilian pump attendants, and concludes that such deficits are correlated with chronic exposure (significant from 8 years of service) with a level of exposure to gasoline and ethanol below the Brazilian tolerance limit, but within an intervention level to gasoline vapor (168 and 153,40 ppm > 150 ppm) according to the Brazilian Standards for Work Health and Safety. / O objetivo deste estudo foi determinar os níveis de exposição aos vapores da gasolina e do etanol e verificar as consequências psicofísicas, neurocognitivas e fisiológicas em uma amostra de frentistas brasileiros. Para avaliar o nível de exposição ambiental foram realizados monitoramentos passivos e ativos de vapor com cromatografia gasosa e sensoriamento microclimático. A avaliação psicofísica foi realizada com os testes cromáticos de Lanthony D15-d e o Cambridge Color Teste 2,0; com a Função de Sensibilidade ao Contraste utilizando grades senoidais verticais e o Metropsis nas frequências 0,2; 0,5; 1,0; 2,0; 5,0; 10,0 e 16,0 cpg e com o rastreamento ocular utilizando um eyetracker 250 Hz. Todos os testes de visão, exceto o D15-d, foram realizados monocularmente com o olho dominante. A avaliação neurocognitiva ocorreu com os testes Trail Making A, B e com a Figura Complexa de Rey. A avaliação fisiológica, após utilização de parâmetros de exclusão, foi realizada pela análise de sangue de 16 frentistas verificando funções hepatotóxicas pelos marcadores Alanina Aminotransferase (ALT), Aspartato Aminotransferase (AST), Bilirrubina Direta (BD), Bilirrubina Total (BT) e Gamaglutamiltraspeptidase (GGT). Utilizou-se ainda o questionário de sintomas Psicológicos e Neurofisiológicos (PNF) além de um questionário sóciodemográfico e os testes de Ishihara e o ―E‖ de Rasquin na triagem. Essa etapa selecionou 38 frentistas do sexo masculino (Grupo Exposto), com idade média de 32,66 anos (DP = 1,30), grau de escolaridade média igual a 9,68 anos de estudo (DP = 0,34) e 38 voluntários (Grupo Controle) também do sexo masculino, sem histórico de exposição a solventes, considerados saudáveis pelos parâmetros de exclusão, com idade média de 31,00 anos (DP = 1,54) e grau de escolaridade médio de 9,84 anos de estudo (DP = 0,34). Não existiu diferença significativa entre a idade (p = 0,224) e o grau de escolaridade (p = 0,52) dos grupos que apresentaram ainda acuidade visual de 20/20 ou corrigida. Pelo teste de Mann-Whitney foram encontradas diferenças significativas entre os escores para: o Índice de Confusão de Cores do teste D15-d (p < 0,01, prevalecendo perdas no eixo tritan 75%), as Áreas das elipses (protan, deutan e tritan, ambos p < 0,05), as frequências 5 cpg, 10 cpg e 16 cpg (ambos p < 0,01), o teste Trail Making A (p < 0,01) e B (p < 0,05), a cópia e a memória da Figura complexa de Rey (ambas p < 0,01) e o número de sacadas e tempo de percurso do labirinto no eyetracker (ambos p < 0,01). A avaliação biológica demonstrou principalmente alterações nos valores da BD (100 % dos frentistas) e BT (62,5 %). Dois frentistas tiveram alterações combinadas de enzimas hepáticas e bilirrubinas. A correlação de Spearman demonstrou a influência do tempo de serviço no acréscimo das áreas protan (ρ = 0,46; p < 0,01) e deutan (ρ = 0,64; p < 0,01), além de correlações com a frequência de 5 cpg (ρ = 0,36; p < 0,05) e com os testes Trail Making A (ρ = 0,40; p < 0,05) e B (ρ = 0,37; p < 0,05). O peso apresentou a tendência de atenuar os déficits nos testes de visão, correlacionando negativamente com a área deutan (ρ = - 0,45; p < 0,01) e positivamente com a sensibilidade ao contraste na frequência 0,20 cpg (ρ = 0,37; p < 0,05). Existiram ainda correlações entre a BD e o tempo para realizar a prova no eyetracker (ρ = 0,58; p < 0,05) e entre o GGT e as queixas de instabilidade psiconeurovegetativa (ρ = 0,57; p < 0,05). Os testes Kruskal Wallis, e Mann- Whitney como post hoc com correção Bonferroni, demonstraram que a partir de 8 anos de exposição existem consequências para a visão de cores (Protan e Deutan) e para processos neurocognitivos relacionados a atenção (Trail Making A). O questionário PNF apontou que 52,60 % dos frentistas possuem sintomas de agressões neuropsicológicas. Além disso, existiram convergências entre as queixas de falta de memória e concentração, com menores pontuações da memória na Figura Complexa de Rey (ρ = - 0,34; p < 0,05). Este estudo confirma e avança nas descobertas de consequências na visão de cores e sensibilidade ao contraste, aponta uma possível etiologia ocupacional nas alterações hepatotóxicas, apresenta as deficiências neurocognitivas nos frentistas brasileiros e conclui que essas deficiências e as da visão de cores estão correlacionadas a uma exposição crônica (significativa aos 8 anos de serviço) com um nível de exposição a gasolina e ao álcool etílico abaixo do Limite de Tolerância brasileiro, mas a um nível de intervenção para o vapor de gasolina (168,00 e 153,40 ppm > 150 ppm) conforme as Normas de Saúde e Segurança do Trabalho brasileiras.

L(objectif de cette thèse a été de développer de nouveaux solvants d'absorption des composés organiques volatils (COV). Ces derniers sont des polluants atmosphériques primaires généralement utilisés comme solvants et émis directement par les industries. Ils induisent des effets nocifs pour la santé, et certains d'entre eux, sont classés comme cancérogènes. La réduction des émissions de ces polluants reste donc une préoccupation majeure. L'objectif de notre travail a été d'évaluer les solvants eutectiques profonds (DES) comme absorbants pour les COV. Les DES représentent une nouvelle génération de solvants. Ils sont formés par simple mélange de 2 ou plusieurs composés. Ils peuvent être produits à partir de composés économiques, naturels et biodégradables. La préparation de ces solvants est facile et permet une économie d'atome de 100%. Le travail a été divisé en trois parties.La première partie a été consacrée à la caractérisation des propriétés physico-chimiques des DES, telles que la densité et la viscosité. L'analyse des spectres infrarouge des DES et de leurs composés purs a montré une implication des liaisons hydrogène dans la formation des DES. La polarité a été étudiée à l'aide de la sonde Nile red. Enfin, la solubilité de gaz (CO₂, CH₄ and Ar) a été mesurée dans les DES en fonction de la température. La deuxième partie a porté sur l'évaluation de la capacité d'absorption des DES en utilisant la technique d'headspace statique couplée à la chromatographie en phase gazeuse. Ceci nous a permis de déterminer le coefficient de partage gaz/liquide pour les COV dans les DES à différentes températures. L'influence des mélanges de COV sur les capacités d'absorption des DES a été également déterminée. Ces derniers ont montré des capacités d'absorption élevées pour la variété de COV, sans saturation même à forte concentration. Un nouveau système DES-cyclodextrine a également été évalué. Les capacités d'absorption ont été améliorées grâce au rôle de molécule cage de la cyclodextrine. La deuxième partie a été tournée vers l'application industrielle. Nous avons évalué les capacités d'absorption des DES à l'aide d'un montage dynamique qui simule une colonne d'absorption industrielle. Cette installation permet de moduler le débit du COV, les teneurs en eau ainsi que la température de la colonne. Enfin, la régénération des DES a été effectuée par plusieurs cycles absorption/désorption sans perte de capacité d'absorption. En conclusion, l'ensemble des résultats obtenus a montré que les DES possédaient de nombreux atouts leur permettant d'être considérés comme des solvants prometteurs pour l'absorption des COV. / The aim of this thesis was to develop new solvents for the absorption of volatile organic compounds (VOC). VOC are primary air pollutants generally used as solvents and emitted directly from industries. They have adverse health effects and some of them are classified as carcinogenic. Consequently, the reduction of the emissions of these pollutants remains a major challenge to reduce air pollution. Hence, our objective was to evaluate deep eutectic solvants (DES) as absorbents for VOCs. DESs represent a new generation of solvents that is formed by simply mixing two or more compounds. They can be produced from cheap, natural and biodegradable compounds. The preparation of these solvents is easy and is 100% atom efficient. This work was divided into three parts.The first part focused on the physicochemical properties of DES, such as density and viscosity. Analysis of the infrared spectra of DES and their pure compounds showed that hydrogen bonds are essential for the formation of DES. Their polarity was studied using the Nile red probe. In addition, solubility of various gases (CO₂, CH₄ and Ar) was measured as a function of temperature. The second part dealt with the evaluation of the aborsption capacity of DESs using static headspace coupled with gas chromatography. The determination of gas/liquid partition coefficient was performed for various VOC and DES at different temperatures. In addition, the influence of VOC mixtures on DES absorption capacities was determined. DES showed high absorption capacities for a variety of VOCs, without saturation even at high concentration. A new DES-cyclodextrin system was developed and showed improved absorption capacities due to the complexation ability of the cyclodextrin. The last part was oriented towards the industrial application of DESs. The absorption capacities of DESs were evaluated using a dynamic set-up which simulated an industrial absorption column. This set-up allows the modulation of the VOC flow rate, water content and column temperature. Finally, the regeneration of the absorbent was carried out by several absorption/desorption cycles without loss of absorption capacity. In conclusion, the overall results showed that DES have characteristics that allow them to be considered as promising solvents for VOC absorption.

Comme de nombreux colloïdes, des nanoparticules métalliques recouvertes de ligands en suspension s’organisent au-delà d’une fraction volumique seuil et forment ce que l’on appelle un « supracristal ». Ce sont ainsi des systèmes modèles, déjà largement étudiés à partir de suspensions dans des solvants volatils, qui permettent de mieux comprendre l’auto-assemblage de sphères déformables. Les interactions qui conduisent à l’auto-assemblage sont couramment décrites par une compétition entre une attraction de van der Waals entre les cœurs métalliques et une répulsion entre les ligands qui va dépendre de l’affinité entre les ligands et le solvant. Un effet du solvant a déjà été observé sur l’auto-organisation de nano-objets. En mesurant par diffusion de rayons X aux petits angles le facteur de structure de suspensions de nanoparticules d’or greffées, j’ai pu sonder de façon systématique les interactions entre des nanoparticules en suspension avec plusieurs tailles de cœur, des ligands alcane-thiols de longueur différente et dans différents solvants à la fois volatils et non volatils. J’ai ainsi pu mettre en évidence une interaction attractive inattendue dans des alcanes linéaires flexibles et dont l’intensité augmente avec la longueur de l’alcane. Pour corréler les interactions entre particules à leur diagramme de phase, j’ai suivi le processus de cristallisation dans des suspensions en solvant volatil ou partiellement volatil ainsi qu’en émulsion, techniques qui permettent d’augmenter lentement la concentration en nanoparticules. Les interactions attractives induites par le solvant contribuent ainsi à la formation de supracristaux à de très faibles fractions volumiques. A de fortes concentrations, la structure des supracristaux ne dépend pas du solvant utilisé mais, à forte densité de greffage, du rapport R entre la longueur des ligands et le diamètre du cœur d’or. Pour un rapport R voisin de 0.7, la structure finale observée est cubique centrée, la structure à concentration intermédiaire étant cubique à faces centrées. Pour un rapport R deux fois plus petit, une structure originale a été mise en évidence. Il s’agit d’une structure hexagonale de grand paramètre de maille, analysée comme une phase de Frank et Kasper de type MgZn2 ou C14. C’est la première fois qu’une telle phase à empilement local tétraédrique est observée dans un système de sphères monodisperses molles. L’existence de cette phase ainsi que le rôle du rapport R a pu être interprétée en estimant quantitativement la compétition entre l’attraction de van der Waals forte et l’entropie des ligands. / As many colloids, metallic nanoparticles grafted with hydrophobic ligands self-assemble above a volume fraction threshold and thus build superlattices. These model systems, which are widely studied when suspended in volatile oils, enable a better understanding of soft spheres self-assembly.Interactions which lead to self-assembly are commonly described by the combination of van der Waals attraction with interaction between the ligand shells. The shell behavior is controlled by the ligand affinity with the solvent. An effect of the solvent on the self-assembly of nanoparticles has already been observed. Using a small angle X-ray scattering, I measured, through the structure factor, the interactions between gold nanoparticles grafted with alkanethiols in different oils, at various concentrations, for different lengths of ligands and core diameters. I noticed an attractive interaction when using flexible linear alkanes as solvent. It has also been shown that the attraction intensity increases with the solvent length.In order to correlate the interactions between particles to their phase diagram, I studied the crystallization process by concentrating nanoparticles using evaporation in capillaries or Ostwald ripening in emulsions. I showed that attractive interactions induced by the solvent lead to superlattices formation at very low volume fractions.At high concentrations, the superlattice structure depends on the ratio of the ligand length over the gold core diameter. For a ratio around 0.7, the final structure observed is body centered cubic, whereas at lower concentration, it is face centered cubic. When this ratio is halved, an unexpected structure is observed. It is a hexagonal structure with a large lattice parameter. It has been analyzed as a Frank and Kasper’s phase named MgZn2 or C14. It is the first time that this topologically close-packed structure is observed for monodisperse soft spheres. The existence of this phase and the role of the ratio R have been interpreted by considering quantitatively the competition between ligands entropy and the strong van der Waals attraction.