Doctor of Philosophy(PhD) / Soil contamination with heavy metal(loid)s is a major environmental problem that requires effective and affordable remediation technologies. The utilisation of plants to remediate heavy metal(loid)s contaminated soils has attracted considerable interest as a low cost green remediation technology. The process is referred to as phytoremediation, and this versatile technology utilises plants to phytostabilise and/or phytoextract heavy metal(loid)s from contaminated soils, thereby effectively minimising their threat to ecosystem, human and animal health. Plants that can accumulate exceptionally high concentrations of heavy metal(loid)s into above-ground biomass are referred to as hyperaccumulators, and may be exploited in phytoremediation, geobotanical prospecting and/or phytomining of low-grade ore bodies. Despite the apparent tangible benefits of utilising phytoremediation techniques, a greater understanding is required to comprehend the ecophysiological aspects of species suitable for phytoremediation purposes. A screening study was instigated to assess phytoremediation potential of several fern species for soils contaminated with cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), lead (Pb) and zinc (Zn). Hyperaccumulation was not observed in any of the studied species, and in general, species excluded heavy metal uptake by restricting their translocation into aboveground biomass. Nephrolepis cordifolia and Hypolepis muelleri were identified as possible candidates in phytostabilisation of Cu-, Pb-, Ni- or Zn-contaminated soils and Dennstaedtia davallioides appeared favourable for use in phytostabilisation of Cu- and Zn-contaminated soils. Conversely, Blechnum nudum, B. cartilagineum, Doodia aspera and Calochlaena dubia were least tolerant to most heavy metals and were classified as being least suitable for phytoremediation purposes Ensuing studies addressed the physiology of arsenic (As) hyperaccumulation in a lesser known hyperaccumulator, Pityrogramma calomelanos var. austroamericana. The phytoremediation potential of this species was compared with that of the well known As hyperaccumulator Pteris vittata. Arsenic concentration of 3,008 mg kg–1 dry weight (DW) occurred in P. calomelanos var. austroamericana fronds when exposed to 50 mg kg–1 As without visual symptoms of phytotoxicities. Conversely, P. vittata was able to hyperaccumulate 10,753 mg As kg–1 DW when exposed to 100 mg kg–1 As without the onset of phytotoxicities. In P. calomelanos var. austroamericana, As was readily translocated to fronds with concentrations 75 times greater in fronds than in roots. This species has the potential for use in phytoremediation of soils with As levels up to 50 mg kg–1. Localisation and spatial distribution of As in P. calomelanos var. austroamericana pinnule and stipe tissues was investigated using micro-proton induced X-ray emission spectrometry (µ-PIXE). Freeze-drying and freeze-substitution protocols (using tetrahydrofuran [THF] as a freeze-substitution medium) were compared to ascertain their usefulness in tissue preservation. Micro-PIXE results indicated that pinnule sections prepared by freeze-drying adequately preserved the spatial elemental distribution and tissue structure of pinnule samples. In pinnules, µ-PIXE results indicated higher As concentration than in stipe tissues, with concentrations of 3,700 and 1,600 mg As kg–1 DW, respectively. In pinnules, a clear pattern of cellular localisation was not resolved whereas vascular bundles in stipe tissues contained the highest As concentration (2,000 mg As kg–1 DW). Building on these µ-PIXE results, the chemical speciation of As in P. calomelanos var. austroamericana was determined using micro-focused X-ray fluorescence (µ-XRF) spectroscopy in conjunction with micro-focused X-ray absorption near edge structure (µ-XANES) spectroscopy. The results suggested that arsenate (AsV) absorbed by roots was reduced to arsenite (AsIII) in roots prior to transport through vascular tissues as AsV and AsIII. In pinnules, AsIII was the predominant species, presumably as aqueous-oxygen coordinated compounds. Linear least-squares combination fits of µ-XANES spectra showed AsIII as the predominant component in all tissues sampled. The results also revealed that sulphur containing thiolates may, in part sequester accumulated As. The final aspect of this thesis examined several ecophysiological strategies of Ni hyperaccumulation in Hybanthus floribundus subsp. floribundus, a native Australian perennial shrub species and promising candidate in phytoremediation of Ni-contaminated soils. Micro-PIXE analysis revealed that cellular structure in leaf tissues prepared by freeze-drying was adequately preserved as compared to THF freeze-substituted tissues. Elemental distribution maps of leaves showed that Ni was preferentially localised in the adaxial epidermal tissues and leaf margin, with concentration of 10,000 kg–1 DW in both regions. Nickel concentrations in stem tissues obtained by µ-PIXE analysis were lower than in the leaf tissues (1,800 mg kg–1 vs. 7,800 mg kg–1 DW, respectively), and there was no clear pattern of compartmentalisation across different anatomical regions. It is possible that storage of accumulated Ni in epidermal tissues may provide Ni tolerance to this species, and may further act as a deterrent against herbivory and pathogenic attack. In H. floribundus subsp. floribundus seeds, µ-PIXE analysis did not resolve a clear pattern of Ni compartmentalisation and suggests that Ni was able to move apoplastically within the seed tissues. The role of organic acids and free amino acids (low molecular weight ligands [LMW]) in Ni detoxification in H. floribundus subsp. floribundus were quantified using high performance liquid chromatography (HPLC) and ultra performance liquid chromatography (UPLC). Nickel accumulation stimulated a significant increase in citric acid concentration in leaf extracts, and based on the molar ratios of Ni to citric acid (1.3:1–1.7:1), citric acid was sufficient to account for approximately 50% of the accumulated Ni. Glutamine, alanine and aspartic acid concentrations were also stimulated in response to Ni hyperaccumulation and accounted for up to 75% of the total free amino acid concentration in leaf extracts. Together, these LMW ligands may complex with accumulated Ni and contribute to its detoxification and storage in this hyperaccumulator species. Lastly, the hypothesis that hyperaccumulation of Ni in certain plants may act as an osmoticum under water stress (drought) was tested in context of H. floribundus subsp. floribundus. A 38% decline in water potential and a 68% decline in osmotic potential occurred between water stressed and unstressed plants, however, this was not matched by an increase in accumulated Ni. The results suggested that Ni was unlikely to play a role in osmotic adjustment in this species. Drought stressed plants exhibited a low water use efficiency which might be a conservative ecophysiological strategy enabling survival of this species in competitive water-limited environments.

The research from this project has quantified the solar UV environment beneath and surrounding typical local council public shade structures. The effects of changing seasons, atmospheric conditions, structural modifications and surrounding plant life on diffuse UV have been quantified. Strategies to improve current shade structures, so as to significantly reduce the levels of diffuse UV reaching the human body in the shade, have also been developed. For the shade structures used in this research it was found that ultraviolet protection factors ranged from 1.5 to 18.3 for a decreasing solar zenith angle. Correlations have been found relating diffuse erythemal UV to UV in the shade for clear skies and a changing solar zenith angle. The effect of changing atmospheric ozone levels on diffuse erythemal UV levels has been quantified. UV exposures were assessed for a decrease in scattered UV beneath specific shade structures by the use of two types of protection, namely, side-on polycarbonate sheeting and evergreen vegetation. Broadband radiometric and dosimetric measurements conducted in the shade of a scale model shade structure, during summer and winter, showed significant decreases in exposure of up to 65% for summer and 57% for winter when comparing the use and non-use of polycarbonate sheeting. Measurements conducted in the shade of four shade structures, with various amounts of vegetation blocking different sides, showed that adequate amounts and positioning of vegetation decreased the scattered UV in the shade by up to 89% when compared to the shade structure that had no surrounding vegetation. This research shows that major UV reduction could be achieved by the ‘shade creation and design industry’, and that shade guidelines should be updated as soon as possible.

By the discovery of the therapeutic properties of ultra-violet light, vast possibilities in the treatment of all tubercular lesions have been opened up. Not the least important of these lesions is lupus vulgaris, which until now has, in many cases, obstinately defied cure. The ultra-violet light universal bath, while still in its childhood regarding experience of technique, etc., has already proved itself the greatest curative agent yet discovered for lupus vulgaris, producing dramatic results in many an old-standing case which has resisted every other method of treatment. In this Thesis I shall endeavour to show the marvellous results of carbon arc-light baths in lupus vulgaris, and though the improvement may appear slow, we must allow for the amount of destruction of shin in the disease, and its many years' duration in most cases.

In Chapter 1, we present the background for transient absorption spectroscopy through the polarization response of a material to an electric field which gives rise to linear and non-linear processes. We then discuss a theoretical description of how vibrational coherences are formed via four-wave mixing and impulsive excitation. We also describe signatures of coherent wavepackets in transient absorption and the application of vibrational coherences, specifically to observe non-radiative processes. We then summarize two previous studies using impulsive transient absorption on cresyl violet, the differences in the coherent dynamics reported, and the motivations behind the experiments presented in this work. Chapter 2 pertains to the apparatus used to perform the transient absorption experiments. We detail the source for the generation of ultrashort laser pulses (durations of less than 10 fs) used for the pump and probe from an argon-based white-light filament and non-colinear optical parametric amplifier. Two-dimensional shearing interferometry, the method used to measure the ultrashort pulses across a large portion of the visible spectrum (500-750 nm), is discussed. The retrieved temporal, spectral, and phase profiles of the pump and probe pulses are presented. Finally, the sample preparation for cresyl violet is described as well as the detection method and data processing used to generate the figures throughout this work. In Chapter 3, we present the results of impulsive transient absorption spectroscopy of cresyl violet perchlorate under four pump conditions. First, we report a study on controlling the formation of vibrational coherences on the ground or excited electronic states of cresyl violet by tuning the pump conditions from an off-resonant to a resonant scheme. The decay of the electronic population and positions of the stimulated emission and excited-state absorption maximums shows a dependence on the pump wavelength. Higher excitation frequencies blueshifts the stimulated emission 18 meV and red shifts excited-state absorption by 4 meV at early times compared to only 13 meV and 2 meV when using lower excitation frequencies. Coherent vibrations are observed and persist for approximately 6 ps after excitation, with phase flips appearing at 593 nm, the absorption maximum, after off-resonant excitation and at the emission (619 nm) and excited-state absorption (500 nm) maximums after resonant excitation. The ground- and excited-state vibrational modes are characterized by Fourier transform Raman spectroscopy. The excited-state vibration spectrum is shown to share nearly identical features as the ground-state, with each vibration slightly red-shifted, 2-10 cm-1, from the corresponding mode in the ground-state, particularly a prominent peak appearing at 594 cm-1 in the ground-state and 589 cm-1 in the excited-state. Next, two additional pump conditions using broadband and partially resonant pump pulses are explored to replicate the conflicting reports of non-adiabatic crossings in cresyl violet. Constant phase-flips observed in the control studies are replaced with phase flips that appear and disappear over several picoseconds. The Fourier Raman spectrum of the coherent signal after broadband excitation displays a mix of ground- and excited-state features, particularly prominent peaks at both 589 cm-1 and 594 cm-1. In Chapter 4, we analyze the coherent signals after broadband excitation using a Fourier filtering technique to isolate the ground- or excited-state coherent dynamics by carefully selecting representative vibrational modes for each state. Using a narrow filter to isolate the 589 cm-1 and 595 cm-1 features in the broadband Fourier Raman spectrum successfully isolates coherent vibrations with phase flips at either the emission and excited-state absorption maximums or the ground-state absorption maximum, respectively. A filter that includes both features generates apparent phase-flips that only appear for ~1ps and at probe wavelengths that do not correspond to the emission or absorption maximums. In Chapter 5, we present a simulation of the coherent signals using a model of two wavepackets with carrier frequencies of 589 cm-1 and 595 cm-1 and dephasing rates of 2 and 3 ps, respectively. Comparison to the broadband pump conditions and Fourier filtered coherent oscillations shows that the complex temporal dynamics observed are adequately described by the linear interference of two vibrational coherences evolving on different electronic potential energy surfaces, without the need to invoke non-adiabatic dynamics. / Chemistry

Biofilms have the potential to form on various abiotic surfaces and have been found to be more resistant to environmental stressors. Therefore, there is a need to investigate the biofilm forming ability and characteristics of Salmonella strains isolated from poultry meat. These studies characterized the biofilm forming capabilities of 5 Salmonella strains on abiotic surfaces, and investigated changes in gene expression that are associated with Salmonella biofilm formation in 3 Salmonella strains. Salmonella biofilms were cultivated on stainless steel, concrete, rubber, and polyethylene under static and shear stress conditions. Biofilm matrix density was determined using a modified crystal violet assay, and attached cells were enumerated by direct plating on tryptic soy agar plates. Additionally, biofilm development was verified using scanning electron microscopy. Extracellular matrix density was affected by a surface-incubation condition interaction, in which the OD600 was higher on stainless steel under shear stress, as compared to static incubation (P < 0.001). On polyethylene, the OD600 was higher under static incubation (P < 0.001). The number of attached cells was highest on polyethylene under shear stress, irrespective of strain (6.4 log/coupon; P < 0.001). The study tracked changes in the expression of the biofilm-associated genes csgD, bapA, bcsA, adrA, and luxS. The gene expression levels in 24 h planktonic cells, 4-day old biofilms, and 5-day old biofilms were compared to those in 12 h planktonic cells and normalized to 16S RNA. Three different Salmonella serovars were used in this study: Salmonella Typhimurium, Reading, and Kentucky. Upregulation of csgD, bcsA, adrA, and luxS at 24 h was observed exclusively in Salmonella Reading (P = 0.028). In 4-day old biofilms, downregulation of all 5 genes was detected (P < 0.001). However, in 5-day old biofilms, the expression of bapA, bcsA, adrA, and luxS increased across all tested Salmonella serovars. These findings highlight the variations in gene expression across different Salmonella serovars, emphasizing the need to remove and prevent Salmonella attachment on food contact surfaces. Through further investigation, it may be possible to establish environmental stress thresholds for biofilm formation and optimize intervention strategies to mitigate Salmonella attachment and persistence on industrial materials.

Climate change and global warming affect both humans and nature in many ways. One of the sectors that is most affected is the agricultural industry because both drought and excessive rainfall pose significant problems. Agricultural lands, especially meadows and pastures, are among the most species-rich environments. Due to changing land use such as exploitation and a challenging economic situation, many farmers choose to terminate their businesses. In Jämtland County, Sweden, the number of notifications to take their agricultural land out of production is increasing, resulting in a decrease in the agricultural land area, which in turn means negative consequences for biodiversity. This study therefore examines the consequence of declining agricultural land areas (pasture land) for a species strongly linked to these environments – the violet copper butterfly (Lycaena helle). The hypothesis is that the violet copper has decreased in occurrence in the last 20 years (2003–2023) as pasture land areas have been reduced in Jämtland. To investigate this, correlation analyzes were made between species observations in Jämtland over the last 20 years (2003–2023) and data for pasture land areas for the same period. The correlation analysis was carried out for species observations from the Swedish Species Observation System (SLU Artdatabanken) and from the Swedish Butterfly Monitoring (Svensk Dagfjärilövervakning) to compare whether the outcomes were different depending on the data source. None of the statistical tests showed any significant positive correlation (p &gt;0.05), which meant that the hypothesis was not correct. In contrast, the correlation results for the two different data sources implied different trends: Swedish Species Observation System's findings shows a negative correlation (r= -0.408; p = 0.074; 2-tailed) indicating an increasing population size and the Swedish Butterfly Monitoring data shows a positive correlation (r= 0.449; p = 0.225; 2-tailed) indicating a decreasing population size. However, estimating total population size is challenging, so targeted repeated inventories on the same sites over a long period of time are recommended (similar to the Swedish Butterfly Monitoring program) to obtain accurate and reliable datasets for analyses. It is difficult to determine whether climate change is directly affecting the violet copper, but the indirect effects such as land use change, exploitation and abandoned agricultural land most likely do. This study further recommends research on the isolation effects on the Swedish population (genetic variation), further consequences of land use change and the species' habitat requirements (ecology). / Klimatförändringarna och den globala uppvärmningen påverkar både människan och naturen på många sett. En av de sektorer som drabbas hårdast är jordbruksverksamheten eftersom dels torka, dels för hög nederbörd innebär stora problem. Jordbruksmarker, framför allt ängs- och betesmarker är en av de artrikaste miljöer som existerar. På grund av förändrad markanvändning som exploatering och en utmanande ekonomisk situation väljer många jordbrukare att lägga ned sina verksamheter. I Jämtland ökar antalet anmälningar att ta sin jordbruksmark ur produktion vilket resulterar i att jordbruksarealen minskar vilket i sin tur innebär negativa konsekvenser för den biologiska mångfalden. Den här studien undersöker därför konsekvensen av minskande jordbruksarealer (betesmarker) för en art som är starkt kopplad till dessa miljöer – violett guldvinge (Lycaena helle). Hypotesen är att violett guldvinge har minskat i förekomst de senaste 20 åren (2003–2023) i takt med att betesmarkarealerna reducerats i Jämtlands län. För att undersöka detta gjordes korrelationsanalyser mellan artfynd i Jämtland de senaste 20 åren (2003–2023) och data för betesmarksarealer för samma period och område. Dels gjordes korrelationsanalysen med fynd från SLU Artdatabanken, dels från Svensk Dagfjärilsövervakning för att jämföra om utfallet blev annorlunda beroende av datakälla. Ingen av de statistiska testerna visade någon signifikant positiv korrelation (p &gt;0,05), vilket innebar att hypotesen inte stämde. Däremot antydde korrelationsresultaten mellan de två olika datakällorna olika trender: SLU Artdatabankens fynd visar en negativ korrelation (r= -0,408; p = 0,074; 2-tailed) vilket indikerar på en ökande population medan Svensk Dagfjärilsövervakning visar en positiv korrelation (r= 0,449; p = 0,225; 2-tailed) vilket indikerar på en minskande population. Att uppskatta populationsstorlekar är dock utmanande, så riktade inventeringar på återkommande lokaler under lång tid rekommenderas (i likhet med Svensk Dagfjärilsövervakning) för att få ackurata och trovärdiga dataset att analysera. Det är svårt att avgöra om klimatförändringarna direkt påverkar den violetta guldvingen, men de indirekta effekterna som förändrad markanvändning, exploatering och övergivna jordbruksarealer gör det sannolikt. Studien rekommenderar vidare forskning kring det svenska beståndets isoleringseffekter (genetisk variation), ytterligare konsekvenser av förändrad markanvändning och artens habitatkrav (ekologi).

Le SiC est un matériau semi-conducteur à large bande d'énergie interdite dont les très bonnes caractéristiques électriques et thermiques en font un candidat idéal pour la fabrication de composants dans le domaine de la puissance et des détecteurs de rayonnement. En particulier, la réalisation de détecteurs UV est très attendue dans les domaines suivants : détection d'incendies, imagerie de surface, astronomie, médecine, militaire… Les photodétecteurs à base de semiconducteurs à large bande interdite permettent d'obtenir une très bonne sélectivité dans l'UV, sans avoir à utiliser de filtres optiques. Le SiC semble être le matériau le plus prometteur, grâce à sa bonne stabilité chimique, mécanique et thermique, ce qui représente un avantage pour opérer en environnement extrême. Cependant le dopage du SiC nécessite un savoir-faire très particulier (implantation à chaud, recuit à haute température, forte dynamique de chauffe…). Nous nous sommes proposés dans un premier temps de réaliser par implantation (ionique et plasma) des composants tests, permettant d'accéder aux caractéristiques des jonctions. Le cas des jonctions implantées n+p et p+n a été étudié. Après l'optimisation des paramètres technologiques de l'implantation et du recuit associé, la fabrication de détecteurs de rayonnement basés sur la diode Schottky ou la diode p.n a été mise en œuvre. Une étape de simulation de ces composants a été effectuée sur le logiciel Sentaurus Device (Synopsys). Les caractérisations de ces détecteurs ont montré une meilleure sensibilité pour les diodes implantées Bore par plasma. / Silicon carbide is a wide band-gap semiconductor with electrical and thermal characteristics particularly suitable for high power devices and radiation sensors. The realisation of UV detectors is mainly useful in the following sectors: fire detection, surface imagery, astronomy, medicine, military... The photodetectors based on wide band-gap semiconductors allow to get a very good selectivity, without using optical filters. Silicon carbide seems to be the most promising material, due to its chemical, mechanical and thermal stability, inducing a reliable behaviour in extreme environment. However SiC doping requires a distinct know-how (hot ion implantation, high temperature annealing, rapid heating-rate…). Test devices have been firstly processed by using ion implantation and plasma, allowing evaluating p+n or n+p junction characteristics. After the optimisation of the technological parameters of implantation and related annealing, the realisation of radiation detectors based on Schottky or p.n diodes has been carried out. The electrical simulations of such devices were performed with Sentaurus Devices program (Synopsys). The characteristics of the devices proved an improvement with the Boron-plasma implantation.

Au cours de cette thèse, de nouveaux dérivés organométalliques basés sur une structure triphénylméthylium ont été synthétisés. Ces composés, notamment grâce à leur structure multiplolaire, sont pressentis pour avoir des propriétés remarquables en optiques non linéaire (ONL) qui pourraient donner lieu à des développements appliqués dans plusieurs domaines. Ces caractéristiques, et plus précisément leur absorption biphotonique (A2P), en font des composés particulièrement intéressants pour l'industrie de pointe (microfabrication, imagerie, dispositifs optiques, etc.). Cependant, ces propriétés d'ONL et d'absorption biphotoniques n'ont été jusqu’à lors que peu étudiées, malgré leur potentiel prometteur. Dans un premier temps, une famille de nouveaux composés organiques présentant cette structure particulière, a donc été synthétisée afin de confirmer le potentiel d'absorption à deux photons de ces chromophores, notamment par des mesures Z-scan. Dans un second temps, la synthèse de d’analogues organométalliques ayant des groupes donneurs tels que «Fe(η5-C5Me5)(κ2-dppe)C≡C− , « Ru(Cl)(κ2-dppe)2C≡C− » ou ethynylferrocene a été réalisée et ces dérivés ont été extensivement caractérisés. Ces dérivés organométalliques devraient présenter des sections efficaces d’A2P (ainsi que des réponses ONL de troisième ordre) dans le proche-IR bien supérieures à celles de leurs analogues organique. De plus les groupements métalliques redox-actifs devraient permettre d’obtenir des chromophores électro-commutables. Dans cet objectif, les études déjà réalisées sur ces composés joints à l’étude à venir de leur propriétés ONL de troisième ordre et permettra de mieux comprendre les phénomènes electroniques sous-jacents à ces propriétés et le rôle joué par les parties organique et organométalliques de leur structure. / During this PhD, new organic and organometallic triphenylmethylium dyes were synthesized. Due to their multipolar structure, these compounds have been anticipated to possess strong nonlinear optical (NLO) properties which could be of interest in many fields. These characteristics, and more precisely their two-photon absorption (TPA) properties, make them attractive for the design of high technology materials (microfabrication, imaging, optical devices, etc…). However, their multiphoton absorption properties and other related nonlinear optical (NLO) effects have not been thoroughly investigated to date, in spite of their promising potential. In this respect, a family of organic derivatives has been synthesized to confirm their potential as two-photon absorbers, which was established thanks to Z-scan measurements. Organometallic compounds bearing electron-releasing groups such as «Fe(η5-C5Me5)(κ2-dppe)C≡C−» , « Ru(Cl)(κ2-dppe)2C≡C− » or ethynylferrocene were then synthesized and fully characterized. These organometallic dyes should possess larger TPA cross-sections (and also larger third-order NLO properties) in the NIR range than their organic counterparts. Furthermore, these redox-active metal centers permit access to electro-switchable molecules. In this respect, along with the data already gathered on these derivatives, the study of their cubic NLO properties in their different redox states will now contribute to a better understanding of the underlying electronic phenomena and the role played by the organic and organometallic moieties in such architectures.

Este trabalho teve como objetivo principal a avaliação do risco ecogenotoxicológico dos corantes Acid Black 210 e Disperse Violet 93, utilizados pelas indústrias têxteis e coureiras nacionais e internacionais. Para atingir este objetivo foi realizada uma abordagem integrada da avaliação da toxicidade utilizando a avaliação da permeabilidade através do Ensaio de Permeabilidade em Membrana Artificial Paralela (PAMPA), a avaliação do potencial genotóxico através do Ensaio do Cometa com células HepG2, a avaliação do potencial mutagênico do através do Teste de Ames com as linhagens de Salmonella typhimurium TA98 e TA100 na ausência e na presença de metabolização exógena (mistura S9), a avaliação do potencial embriotóxico através do Ensaio de Toxicidade Aguda com Embriões de Zebrafish (Danio rerio), e, por fim, juntando os dados disponíveis na literatura científica, a avaliação do risco ecogenotoxicológico da utilização deste corante têxtil. Devido à observação de ausência de toxicidade nos ensaios realizados e nas informações constantes da literatura científica, não há indícios de que o Acid Black 210 apresente ecogenotoxicidade, podendo ser considerado seguro à luz dos conhecimentos atuais. Ainda, este trabalho apresenta a avaliação do potencial genotóxico do corante Disperse Violet 93 através do Ensaio do Cometa e a avaliação do potencial embriotóxico deste corante através do Ensaio de Toxicidade Aguda com Embriões de Zebrafish (Danio rerio). Considerando que houve toxicidade morfofisiológica em embriões de zebrafish e que na literatura científica também consta sua mutagenicidade em linhagem de S. typhimurium YG1041, o Disperse Violet 93 necessita de avaliações nos demais níveis tróficos para que uma avaliação do risco seja realizada. Para finalizar, este trabalho apresenta a avaliação do potencial embriotóxico de efluente de curtume pré e pós-tratamento através do Ensaio de Toxicidade Aguda com Embriões de Zebrafish, onde o efluente pós-tratamento mostrou menor potencial embrio-tóxico, porém ambos apresentando (mesmo após diluições) coagulação de ovos fertilizados, edema do saco vitelínico, escoliose, má-formação da cauda e má-formação da bexiga natatória. Estes resultados ressaltam a importância da realização de estudos toxicológicos visando fornecer subsídios para a realização de avaliações do risco do uso de corantes, já que estes se encontram em exposição constante aos seres vivos e ao meio ambiente / This study had as main objective the evaluation of the ecogenotoxicologic risk of the Acid Black 210 and Disperse Violet 93 dyes, used by national and international textile and tanneries industries. To achieve this goal was accomplished an integrated approach to evaluate the risk assessment with the permeability through the Parallel Artificial Membrane Permeability Assay (PAMPA), the evaluation of the genotoxic potential using the Comet Assay with HepG2 cells, the assessment of the mutagenic potential through the Ames Assay with the Salmonella typhimurium TA98 and TA100 strains in the absence and presence of exogenous metabolism (S9), the evaluation of the embryo-toxic potential through the Zebrafish (Danio rerio) Embryo Acute Toxicity Test, and, finally, joining the data available in the scientific literature, the evaluation of ecogenotoxicologic risk of using this textile dye. Due to the observation of the absence of toxicity in the testes performed and the information available in the scientific literature, there is no indication that the Acid Black 210 dye has any ecogenotoxicity, and it can be considered safe in the light of current knowledge. Additionally, this study presents the evaluation of the genotoxic potential of the Disperse Violet 93 dye by the Comet Assay and the assessment of embryo-toxic potential of this dye through the Zebrafish (Danio rerio) Embryo Acute Toxicity Test. Considering the observed morphophysiological toxicity in zebrafish embryos and the mutagenicity in S. typhimurium YG1041 strain described by the scientific literature, the Disperse Violet 93 dye needs more studies in other trophic levels to perform its risk assessment. Finally, this study presents the assessment of embryo-toxic potential of effluent pre tannery and aftercare through the Zebrafish (Danio rerio) Embryo Acute Toxicity Test, where the post-treatment effluent showed less embryo-toxic potential, but both presented (even after dilution) coagulation of fertilized eggs, yolk sac edema, scoliosis, malformation of the tail and malformation of the swim bladder. These results highlight the importance of conducting toxicological studies to provide input data for conducting risk assessments of the use of dyes, as they are in constant exposure to the living organisms and the environment

Cyclotides are a family of small and macrocyclic proteins that have been found in Violacaee and Rubiaceae plant species. These proteins contain a cystine knot: two disulfides bonds together with their connecting peptide backbone form an embedded ring which is penetrated by a third disulfide bond. The cyclotides have been attributed a wide range of biological activities, which in combination with their chemical stability and structural plasticity have made them attractive tools for pharmaceutical applications. The sequence of eleven novel cyclotides, vibi A-K, from Viola biflora was determined by the use of both chemical (extraction and characterization) and molecular biology (cDNA analyses) approaches. A clear discrepancy in the results from the two methods was observed. Additionally, one novel cyclotide, vodo O, was isolated from Viola odorata. To correlate cytotoxic potency to sequence, vodo O and vibi D, E, G and H were tested on a lymphoma cell line. Based on the presence or absence of a cis-Pro bond, the cyclotides are divided into the Möbius and bracelet subfamilies. The bracelet proteins have a higher net charge and are more cytotoxic potent than the Möbius ones. To explore these differences, charged and hydrophobic residues in varv A (Möbius) and cycloviolacin O2 (bracelet) were chemically modified and tested for their cytotoxicity. The net-charge of the two proteins was not important for the potency. The Glu residue in cycloviolacin O2 was crucial, while this residue was of minor importance in varv A. Oxidation of the single Trp residue declined the potency significantly in both proteins. To evaluate how the surface properties correlate to the degree of cytotoxic potency, models of all cyclotides hitherto tested were constructed by homology modelling. Calculations showed that the membrane orientation of varv A and cycloviolacin O2 differed significantly, which might explain their difference in potency