No description available.

Este trabalho consistiu no desenvolvimento de um sistema para medir a magnetização de amostras paramagnéticas e diamagnéticas em grandes volumes. Sua principal aplicação tem sido a medida susceptométrica do tecido hepático para a quantificação da sobrecarga de ferro no fígado. Esse excesso de ferro no corpo é comum em pacientes talassêmicos e falcêmicos, que são regularmente submetidos a transfusões de sangue e, em pacientes com hemocromatose. Em pessoas normais, esse depósito de ferro pode conter entre 0,1 e 0,5 mg de ferritina (ftn) por grama de tecido úmido (mg ftn/gtecido úmido). Quando com sobrecarga, pode alcançar até 30 mg ftn/gtecido úmido. A contribuição diamagnética devido à presença dos tecidos biológicos (água, pele, gordura, músculo, nervo, osso, etc) é equivalente à contribuição paramagnética devido à presença de, aproximadamente, 6 mg ftn/gtecido úmido distribuídos no tecido hepático. Essa intensa contribuição diamagnética foi sensivelmente reduzida com o uso de uma bolsa de água acoplada ao torso. Medidas in vitro foram realizadas num phantom, composto de um tubo cilíndrico de acrílico preenchido com água e uma esfera de plástico, acoplada internamente ao cilindro, preenchida com solução de Fe3+. O volume cilíndrico representa os tecidos e o esférico representa o fígado. Medidas in vivo foram realizadas com duas modalidades: com e sem o uso da bolsa de água sobre o torso. Essas medidas foram efetuadas em voluntários assintomáticos e pacientes talassêmicos sob tratamento no Hemocentro de Ribeirão Preto (HRP). A medida da magnetização foi realizada com um gradiômetro axial de segunda ordem, acoplado a um SQUID-RF. A amostra foi magnetizada com um campo magnético AC e homogêneo. Os resultados confirmaram a sensibilidade da técnica para quantificar níveis de ferro hepático em pacientes com sobrecarga, com eficiência de diferenciar níveis equivalentes àqueles encontrado(s) em pessoas normais. A automatização da instrumentação e a aquisição dos dados foram feitas em ambiente LabView e as simulações dos modelos, apresentadas juntamente com os processamentos dos sinais, foram realizadas em ambiente MatLab. / This work consisted in the development of a system to measure the magnetization of large paramagnetic and diamagnetic samples. The main application was susceptometric measurements of the hepatic tissue for quantification of the iron overload. Iron excess is commonly observed in thalassemic and sickle cell anemia patients who have repeatedly received red blood cell transfusions for prevention or treatment of chronic complications and in patients with hemocromatosis. In normal subjects, iron concentration is usually between 0.1 and 0.5 mg of ferritin by gram of wet tissue (mg ftn/gwet tissue). However, in individuals with the above diseases, it can reach up to 30 mg ftn/gwet tissue. The diamagnetic contribution due to the presence of biological tissues (water, skin, fat, muscle, nerve, bone, etc) is equivalent to the paramagnetic contribution due to the presence of approximately 6 mg ftn/gwet tissue distributed in the hepatic tissue. This intense diamagnetic contribution was makedly reduced by using a water bag coupled to the subject’s torso. Measurements in vitro were performed in a phantom composed of a cylindrical acrylic tube, filled with pure water containing a plastic sphere placed off axis to simulate the liver position. The sphere was filled with a Fe3+ solution to simulate different iron concentration present in the liver. Measurements in vivo were performed in thalassemic patients undergoing treatment at the Hemocentro de Ribeirão Preto (HRP) and in normal subjects using two different modalities: with and without the use of the water bag on the torso. The measurements of the magnetization were made using a second order axial gradiometer coupled to a RF SQUID. The sample was magnetized using a homogeneous AC magnetic field. The results confirmed the sensitivity of the technique to quantify levels of hepatic iron in patients with overload, with efficiency of differentiating iron levels equivalent to that found in normal subjects. Automation of instrumentation and data acquisition were done in LabView (National Instruments) and susceptometric models simulations and the signal processing were done in MatLab environment.

« Etude du comportement paramagnétique des actinides en solution avec des ligands polyaminocarboxylates cycliques »Le comportement paramagnétique des cations actinide (éléments 5f) peut être étudié via la spectroscopie RMN liquide en suivant deux axes de recherche complémentaires : les susceptibilités magnétiques et les déplacements chimiques.Dans un premier temps, lorsque les interactions entre le cation actinide et le ligand sont négligeables, la susceptibilité magnétique molaire est accessible par la méthode d’Evans. Cette méthode est applicable pour des échantillons en solution autour de la température ambiante. Elle a été confrontée à la mesure SQUID sur échantillon solide à très basses températures pour le complexe [NpO2(DPC)2Li2]. Les deux méthodes ont donné des susceptibilités magnétiques molaires du même ordre de grandeur même si ce composé n’est pas optimal pour la comparaison.La méthode d’Evans a été utilisée pour compléter les données expérimentales de la littérature. La mesure de la susceptibilité magnétique du cation PuVO2+ (5f3) en milieu non complexant a été mesurée au laboratoire. Les calculs de susceptibilités magnétiques molaires réalisés par la méthode SO-CASPT2 pour les cations actinide aux degrés d’oxydation (+IV), (+V) et (+VI) (AnIV = UIV, NpIV, PuIV et AnV/VI = NpV/VI, PuV/VI) en milieux non complexant puis complexants chlorure et nitrate ont été comparés avec les valeurs expérimentales. Les cations actinide ont montré une sensibilité à la nature et géométrie de leur première sphère de coordination. Il a été mis en évidence que le cation NpVI (5f1) possède un état fondamental sensiblement affecté par la modification de la symétrie du complexe. A partir des niveaux électroniques calculés, des premiers calculs de spectres d’absorption de ces mêmes complexes ont pu être réalisés. L’absorbance principale calculée est en bon accord avec les spectres d’absorption expérimentaux malgré un décalage systématique des spectres calculés vers le rouge, assimilable à un effet néphélauxétique.Dans un deuxième temps, l’utilisation de la Théorie de Bleaney a permis l’étude des déplacements chimiques et plus précisément, du terme de contact des complexes de symétrie C4 d’actinide au degré d’oxydation (+IV) avec le ligand DOTA (AnIV = ThIV, UIV, NpIV, PuIV). Cette contribution de contact a été accessible par la RMN de l’oxygène 17 (17O), atome directement lié au centre paramagnétique. Le DOTA a été enrichi en 17O avant la synthèse du complexe en phase organique DMSO/CHCl3. Ces complexes ont été caractérisés par spectrophotométrie UV-Visible-NIR et spectroscopie RMN 1H et 13C. Une difficulté de synthèse a été rencontrée pour le complexe de ThIV-D17OTA, composante diamagnétique nécessaire à l’extraction des termes de contact purement paramagnétiques. D’autres voies de synthèses ont été explorées.Mots Clés : Actinides, RMN, Paramagnétisme, Susceptibilité magnétique, Déplacement chimique, DOTA.2018 – Commissariat à l’Energie Atomique et aux Energies Alternatives – Laboratoire d’interactions Ligand-Actinide – France / “Study of actinide’s paramagnetic behavior in solution with cyclic polyaminocarboxylate ligands”The actinide cation’s (5f elements) paramagnetic behavior may be studied by liquid NMR spectroscopy. Two complementary lines of research have been pursued: molar magnetic susceptibility and chemical shift.Firstly, magnetic susceptibility is easy to determine by the Evans’ method when there is no interaction between actinide cations and ligands. This method, with samples in solution at room temperature, has been compared to SQUID measurements using solid samples at very low temperatures for the [NpO2(DPC)2Li2] complex. Both methods produce molar magnetic susceptibilities with the same order of magnitude even if this compound is not the best one to the comparison.The Evans’ method has been used to complete experimental data from literature. The molar magnetic susceptibility measurement in a non-complexing medium for the PuVO2+ (5f3) cation has been measured in the laboratory. Molar magnetic susceptibility calculations were carried out using the SO-CASPT2 method for (+IV), (+V) and (+VI) actinide cations (AnIV= UIV, NpIV, PuIV and AnV/VI: NpV/VI, PuV/VI) in a non-complexing medium, then in chloride and nitrate complexing media. They have been compared with experimental values. The molar magnetic susceptibilities of actinide cations have been shown to be sensitive to the nature and geometry of their first coordination sphere. It has been revealed that the fundamental state of NpVI (5f1) cation is affected by changing the symmetry of the complex. From calculated electronic states, first absorption spectra calculations of these complexes have been carried out. A good matching between major calculated and experimental absorbances has been obtained. A red-shift was applied to the calculated absorption spectra to fit better with the experimental ones. This shift may be related to a nephelauxetic effect.Secondly, the use of Bleaney’s Theory has allowed the study of chemical shifts. And precisely, this work has been focused on the contact contribution for C4 symmetry AnIV complexed with DOTA ligand (AnIV= ThIV, UIV, NpIV, PuIV). This contact contribution is observable via NMR of oxygen-17 (17O) because oxygen atoms are directly linked to the paramagnetic cation. Therefore, the DOTA ligand was enriched in 17O before the actinide complex synthesis in a DMSO/CHCl3 organic phase. These complexes have been characterized by UV-Visible-NIR spectrophotometry and 1H, 13C NMR spectroscopy. But, some synthesis difficulties have been encountered to the diamagnetic ThIV-D17OTA (5f0) complex. This diamagnetic component is required to extract pure paramagnetic contact contribution. In that case, other ways of synthesis have been investigated.Keywords: Actinides, NMR, Paramagnetism, Magnetic susceptibility, Chemical shift, DOTA ligand.2018 – Commissariat à l’Energie Atomique et aux Energies Alternatives – Laboratoire d’interactions Ligand-Actinide – France

Thesis (M.S.)--West Virginia University, 2004 / Title from document title page. Document formatted into pages; contains vi, 30 p. : ill. (some col.) Includes abstract. Includes bibliographical references (p. 29-30).

Orientador: Pascoal J. G. Pagliuso / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Fisica Gleb Wataghin / Made available in DSpace on 2018-08-10T11:33:54Z (GMT). No. of bitstreams: 1 Iwamoto_WellingtonAkira_M.pdf: 1834376 bytes, checksum: f57724e8570a2064285943632257620b (MD5) Previous issue date: 2007 / Resumo: Semicondutores ferromagnéticos (FM) são compostos de grande interesse tecnológico devido à possibilidade de combinar suas cargas e o grau de liberdade de spin para produzir dispositivos eletrônicos. Em particular, filmes finos semicondutores dopados com metais de transição têm se tornado foco de intensa investigação científica desde a descoberta do ferromagnetismo com razoável temperatura de Curie [1] ¿[4]. Exemplos de semicondutores magnéticos diluídos (DMS) são os filmes finos de GaAs dopado com Mn e ZnO dopado Co. Nessa dissertação, nós apresentamos experimentos de Ressonância Paramagnética Eletrônica (EPR) e de susceptibilidade magnética para os filmes finos amorfos e cristalinos de GaAs dopados com Mn e filmes cristalinos de ZnO dopados com Co, com a finalidade de explorar as propriedades magnéticas globais e locais nesses DMS. Para todos os filmes amorfos de GaAs dopados com Mn, os nossos resultados indicaram a ausência de qualquer ordenamento ferromagnético entre as temperaturas 300 > T > 2 K ao contrário dos filmes cristalinos que foi observado ferromagnetismo em T < 110 K. Além do mais, observamos nas medidas de EPR uma única linha associada aos íons localizados de Mn 2+ para os filmes finos amorfos de GaAs dopados com Mn e g ~ 2,01, o qual se manteve inalterado com a temperatura. Para nossos filmes cristalinos de GaAs foram observados modos ferromagnéticos para T < TC. Alguns filmes amorfos de GaAs dopado com Mn, foram hidrogenados e, para estes, encontramos que dopagem de hidrogênio, torna o filme mais cristalino, e que sua influência nas propriedades magnéticas é somente causada pela sua variação no grau de cristalinidade. Para os filmes cristalinos de ZnO dopado com Co, os experimentos de EPR mostraram que somente para os filmes com concentração de 10 % de Co um modo ferromagnético pôde ser observado. E através de medidas de magnetização foi observada uma magnetização de saturação máxima MS ~ 1,1 µB/Co para o filme com concentração de 10 % de Co, sendo que a magnetização decresce para concentrações maiores de Co. Isso indica que o loop ferromagnético encontrado nos filmes não pode estar associado a simples precipitação de Co. Uma comparação entre as propriedades magnéticas do filmes de 10 % de Co e da possível fase espúria, ZnCo2O4, mostraram propriedades magnéticas dos filmes de ZnO dopado com Co não parecem estar associados com esta fase / Abstract: Ferromagnetic semiconductors (FM) are compounds of technological interest due to the possibility of combining their charge and spin degrees of freedom when producing electronic devices. In particular, semiconductor thin films doped with transition metal have become focus of intense scientific investigation since ferromagnetism with reasonably high Curie temperatures (racing from few Kelvin to room temperature) was found in theses films [1-4]. Examples of such dilute magnetic semiconductor (DMS) are Mn-doped GaAs and Co-doped ZnO thin films. ZnO is a direct bandgap II-VI semiconductor with a wurtzite-type structure. In this word, we have performed studies of EPR and magnetic susceptibility in Co-doped ZnO and Mn-doped GaAs thin films in order to further explore the global and local magnetic properties of these intriguing DMS. For the Mn-doped GaAs samples, our results show the absence of ferromagnetic ordering for the amorphous films in the 300 > T > 2 K temperature range, in contrast to the ferromagnetism found in crystalline films for TC< 110 K. A single EPR line with a temperature independent g-value (g ~ 2) is observed for the amorphous films and the behavior of this ESR linewidth depends on the level of crystallinity of the film. For the Mn-doped GaAs crystalline films, only a ferromagnetic mode is observed for T < TCwhen the film is ferromagnetic. Regarding the effect of H-doping in the properties of Mn-doped GaAs amorphous films, the Mn 2+ ESR line was found to be nearly unaffected by the presence of hydrogen apart of slightly linewidth changes induced by the changes in the film crystallinity. Hydrogen doping has no direct effects in the magnetic properties of Mn-doped GaAs films. For the Co-based films, the ESR experiments show that only the Zn0,90Co0,10 O film presented a strong anisotropic FMR. The magnetization data show that ~ 10% of Co-doped ZnO films produce the maximum Ms ~ 1,1 µB/Co in the series. The absence of FMR for films with higher Co Concentration indicates that the observed FM loops cannot be associated with simply precipitation of pure Co ions, but more work needs to be done to complete rule out the contribution of other magnetic secondary phases / Mestrado / Física da Matéria Condensada / Mestre em Física

Este trabalho consistiu no desenvolvimento de um sistema para medir a magnetização de amostras paramagnéticas e diamagnéticas em grandes volumes. Sua principal aplicação tem sido a medida susceptométrica do tecido hepático para a quantificação da sobrecarga de ferro no fígado. Esse excesso de ferro no corpo é comum em pacientes talassêmicos e falcêmicos, que são regularmente submetidos a transfusões de sangue e, em pacientes com hemocromatose. Em pessoas normais, esse depósito de ferro pode conter entre 0,1 e 0,5 mg de ferritina (ftn) por grama de tecido úmido (mg ftn/gtecido úmido). Quando com sobrecarga, pode alcançar até 30 mg ftn/gtecido úmido. A contribuição diamagnética devido à presença dos tecidos biológicos (água, pele, gordura, músculo, nervo, osso, etc) é equivalente à contribuição paramagnética devido à presença de, aproximadamente, 6 mg ftn/gtecido úmido distribuídos no tecido hepático. Essa intensa contribuição diamagnética foi sensivelmente reduzida com o uso de uma bolsa de água acoplada ao torso. Medidas in vitro foram realizadas num phantom, composto de um tubo cilíndrico de acrílico preenchido com água e uma esfera de plástico, acoplada internamente ao cilindro, preenchida com solução de Fe3+. O volume cilíndrico representa os tecidos e o esférico representa o fígado. Medidas in vivo foram realizadas com duas modalidades: com e sem o uso da bolsa de água sobre o torso. Essas medidas foram efetuadas em voluntários assintomáticos e pacientes talassêmicos sob tratamento no Hemocentro de Ribeirão Preto (HRP). A medida da magnetização foi realizada com um gradiômetro axial de segunda ordem, acoplado a um SQUID-RF. A amostra foi magnetizada com um campo magnético AC e homogêneo. Os resultados confirmaram a sensibilidade da técnica para quantificar níveis de ferro hepático em pacientes com sobrecarga, com eficiência de diferenciar níveis equivalentes àqueles encontrado(s) em pessoas normais. A automatização da instrumentação e a aquisição dos dados foram feitas em ambiente LabView e as simulações dos modelos, apresentadas juntamente com os processamentos dos sinais, foram realizadas em ambiente MatLab. / This work consisted in the development of a system to measure the magnetization of large paramagnetic and diamagnetic samples. The main application was susceptometric measurements of the hepatic tissue for quantification of the iron overload. Iron excess is commonly observed in thalassemic and sickle cell anemia patients who have repeatedly received red blood cell transfusions for prevention or treatment of chronic complications and in patients with hemocromatosis. In normal subjects, iron concentration is usually between 0.1 and 0.5 mg of ferritin by gram of wet tissue (mg ftn/gwet tissue). However, in individuals with the above diseases, it can reach up to 30 mg ftn/gwet tissue. The diamagnetic contribution due to the presence of biological tissues (water, skin, fat, muscle, nerve, bone, etc) is equivalent to the paramagnetic contribution due to the presence of approximately 6 mg ftn/gwet tissue distributed in the hepatic tissue. This intense diamagnetic contribution was makedly reduced by using a water bag coupled to the subject’s torso. Measurements in vitro were performed in a phantom composed of a cylindrical acrylic tube, filled with pure water containing a plastic sphere placed off axis to simulate the liver position. The sphere was filled with a Fe3+ solution to simulate different iron concentration present in the liver. Measurements in vivo were performed in thalassemic patients undergoing treatment at the Hemocentro de Ribeirão Preto (HRP) and in normal subjects using two different modalities: with and without the use of the water bag on the torso. The measurements of the magnetization were made using a second order axial gradiometer coupled to a RF SQUID. The sample was magnetized using a homogeneous AC magnetic field. The results confirmed the sensitivity of the technique to quantify levels of hepatic iron in patients with overload, with efficiency of differentiating iron levels equivalent to that found in normal subjects. Automation of instrumentation and data acquisition were done in LabView (National Instruments) and susceptometric models simulations and the signal processing were done in MatLab environment.

The mobility of N-alkyl nicotinamides and their solubilization equilibria in surfactant micellar solution were investigated using an NMR paramagnetic relaxation method. The spin-lattice relaxation times (Tl) . for protons of these compounds were measured in pure D20 and in cationic surfactant solution in the presence and absence of · a low concentration of paramagnetic Ma2+ ions. The rotational motion of these molecules in aqueous phase became slower when the alkyl group changed from methyl to octyl. The increase of the 1H spinlattice relaxation rate (Rl) of the molecules, when surfactants are added, implies the penetration of these solubilizates into micellar phase. The micelle to water phase distribution coefficient, 1-p, was determined by monitoring the change of Rl of the solubilizates upon addition of paramagnetic ions to the aqueous phase. The mole fraction based distribution coefficient, Kx, as well as the free energy of transfer of N-alkyl nicotinamides from the aqueous phase to the micellar phase were calculated. A model was postulated for the interaction of N -alkyl nicotinamide with micelles. Hydrophobic force between the alkyl chains of the solubilizates and the surfactants accounts for the solubilization of N -alkyl nicotinamides and can force the binding of cationic compounds to cationic micelles · despite charge repulsion. With increasing of the alkyl chain length, the hydrophobic force increases, and the interaction between them becomes stronger, and more N -alkyl nicotinamides are solubilizated into the micellar phase.

Controlled cell assembly is essential for fabricating in vitro models that mimic native tissue architecture. Conventional tissue engineering techniques are time-consuming and offer limited control over the spatial organization of cells within the assembled cell aggregates. We describe a label-free, scaffold-free, rapid cell manipulation technique to assemble cells into layered aggregates. Suspensions of cells in a culture medium with higher magnetic susceptibility are seeded into wells of a 96-well plate placed on a quartet magnet array. An FDA-approved paramagnetic agent is added to the regular cell culture medium to enhance the magnetic susceptibility. The inhomogeneous magnetic field and the susceptibility difference drive cells toward the lowest magnetic field region on the well surface. Two cell types are sequentially added to the wells to form layer-on-layer aggregates within 6 h. Next, the label-free technique is extended to develop a cell migration assay. Besides being time-consuming, the traditional scratch-based cell migration assay is not reproducible, whereas the alternate physical barrier-based method is expensive. Annular aggregates of human bronchial epithelial cells (HBEC3 KT) are formed within 3 h using a coaxially arranged ring-cylinder magnet array. The effects of the paramagnetic agent on cell viability, metabolism, and transcriptional profiles are investigated. The closures of the circular cell-free areas enclosed by HBEC3 KT are analyzed at different times in response to various signaling molecules and surface conditions. Further, we demonstrate the formation of the annular aggregates on human lung fibroblast-laden collagen hydrogel surfaces. The cell-free area closures on hydrogel surfaces in response to signaling molecules are analyzed. The high reproducibility and scalability of the label-free method make it amenable for preclinical research. / Thesis / Doctor of Philosophy (PhD) / Cell cultures are essential tools for studying cell functions under controlled conditions. A better understanding of cell behavior in tissues is required to develop effective treatments for diseases. The organized arrangement of cells in tissues controls tissue functions. The existing culture techniques are time-consuming and have limited control over the cellular arrangement. We describe a simple, rapid, and inexpensive bioprinting technique to arrange cells in layers, which resembles the cellular organization in tissues, such as the skin. The layered structures are formed in standard well plates within 6 h. Cell movement is an essential cell function in various biological processes, such as wound healing. Using the bioprinting method, we form ring-shaped cellular structures within 3 h to study cell movements in response to various signals. The ring structures enclose cell-free areas, which are populated over time as the cells move from the ring into the cell-free regions. The bioprinting method is easy to use and can rapidly form organized cellular structures for drug testing.

Polycrystalline Zn1-xCrxO (0.01 ≤ x ≤ 0.09) samples synthesized by solid state reaction technique were sintered at different temperatures following slow step sintering schedule. Structural, micro-structural, optical, magnetic properties and homogeneity were investigated using suitable characterisation techniques. Cr2O3 and CrO2 phases have been detected in the XRD patterns and Raman spectra of Zn1-xCrxO samples with x ≥ 0.05. Photoluminescence study has indicated improved optical property of the samples compared to undoped ZnO. While low percentage Cr doped samples showed diamagnetic behaviour, higher percentage doped samples (≥ 5%) exhibited ferromagnetic, paramagnetic and anti-ferromagnetic behaviours depending upon the sintering temperatures. The magnetic properties have been analysed through Electron Spin Resonance study. A g-value of 1.97 indicates Cr in +3 valence state in doped ZnO system. Presence of Cr3+ and Cr4+ in ZnO is understood to facilitate super exchange interactions to promote ferromagnetism at room temperature. ESR study shows improved magnetic homogeneity achieved by slow step sintering process. / Physics / M. Sc. (Physics)

Quasi-one-dimensional quantum models are ideal for theoretically exploring the physical phenomena associated with strong correlations. In this thesis we study three examples where strong correlations play an important role in the static or dynamic properties of the system. Firstly, we examine the behaviour of a doped fermionic two-leg ladder in which umklapp interactions are present. Such interactions arise at special band fillings and can be induced by the formation of charge density wave order in an array of two-leg ladders with long-range (three-dimensional) interactions. For the umklapp which arises from the half-filling of one of the bands, we show that the low-energy theory has a number of phases, including a strong coupling regime in which the dominant fluctuations are superconducting in nature. These superconducting fluctuations carry a finite wave vector – they are the one-dimensional analogue of Fulde-Ferrell-Larkin-Ovchinnikov superconductivity. In a second example, we consider a quantum spin model which captures the essential one-dimensional physics of CoNb₂O₆, a quasi-one-dimensional Ising ferromagnet. Motivated by high-resolution inelastic neutron scattering experiments, we calculate the dynamical structure in the paramagnetic phase and show that a small misalignment of the transverse field can lead to quasi-particle breakdown – a surprising broadening in the single particle mode observed in experiment. Finally, we study the out-of-equilibrium dynamics of a model with tuneable integrability breaking. When integrability is broken by the presence of weak interactions, we show that the system relaxes to a non-thermal state on intermediate time scales, the so-called “prethermalization plateau”. We describe the approximately stationary behaviour in this regime by constructing a generalised Gibbs ensemble with charges deformed to leading order in perturbation theory. Expectation values of these charges are time-independent, but interestingly the charges do not commute with the Hamiltonian to leading order in perturbation theory. Increasing the strength of the integrability breaking interactions leads to behaviour compatible with thermalisation. In each case we use a combination of perturbative analytical calculations and non-perturbative numerical computations to study the problem at hand.