60 research outputs found
Quantum phases of strongly interacting bosons on a two-leg Haldane ladder
No full textWe study the ground-state physics of a single-component Haldane model on a hexagonal two-leg ladder geometry with a particular focus on strongly interacting bosonic particles. We concentrate our analysis on the regime of less than one particle per unit cell. As a main result, we observe several Meissner-like and vortex-fluid phases, both for a superfluid as well as a Mott-insulating background. Furthermore, we show that for strongly interacting bosonic particles, an unconventional vortex-lattice phase emerges, which is stable even in the regime of hard-core bosons. We discuss the mechanism for its stabilization for finite interactions by a means of an analytical approximation. We show how the different phases may be discerned by measuring the nearest- and next-nearest-neighbor chiral currents as well as their characteristic momentum distributions
Praise and Promises
No full textDuring the past 20 years, equality jurisprudence has not followed a straight line. But it does have points and patterns. This paper offers 15 points about section 15 that are divided into two categories: reasons for praise, and promises still to keep. They aim to place the jurisprudence in a celebratory, comparative, and critical context. Many of us reflecting upon the past 20 years have personal memories of the Charter’s entrenchment in 1982 and section 15’s activation in 1985. Legal events and processes are intertwined with personal stories. While the author connect points in a particular way, draw your own web through the m and add other ones, too
Prediction of structures and properties of high-pressure solid materials using first principles methods
No full textThe purpose of the research contained in this thesis is to allow for the prediction of new structures and properties of crystalline structures due to the application of external pressure by using first-principles numerical computations. The body of the thesis is separated into two primary research projects.
The properties of cupric oxide (CuO) have been studied at pressures below 70 GPa, and it has been suggested that it may show room-temperature multiferroics at pressure of 20 to 40 GPa. However, at pressures above these ranges, the properties of CuO have yet to be examined thoroughly. The changes in crystal structure of CuO were examined in these high-pressure ranges. It was predicted that the ambient pressure monoclinic structure changes to a rocksalt structure and CsCl structure at high pressure. Changes in the magnetic ordering were also suggested to occur due to superexchange interactions and Jahn-Teller instabilities arising from the d-orbital electrons. Barium chloride (BaCl) has also been observed, which undergoes a similar structural change due to an s – d transition, and whose structural changes can offer further insight into the transitions observed in CuO.
Ammonia borane (NH3BH3) is known to have a crystal structure which contains the molecules in staggered conformation at low pressure. The crystalline structure of NH3BH3 was examined at high pressure, which revealed that the staggered configuration transforms to an eclipsed conformation stabilized by homopolar B–Hδ-∙∙∙ δ-H–B dihydrogen bonds. These bonds are shown to be covalent in nature, comparable in bond strength to conventional hydrogen bonds, and may allow for easier molecular hydrogen formation in hydrogen fuel storage
Vortex-Hole Duality: A Unified Picture of Weak- and Strong-Coupling Regimes of Bosonic Ladders with Flux
No full textTwo-leg bosonic ladders with flux harbor a remarkable vortex-hole duality between the weak-coupling vortex lattice superfluids and strong-coupling charge-density-wave crystals. The strong-coupling crystalline states, which are realized in the vicinity of ? flux, are independent of particle statistics, and are related to the incompressible fractional quantum Hall states in the thin-cylinder limit. These fully gapped ground states, away from ? flux, develop nonzero chiral (spin) currents. Contact-interacting quantum gases permit exploration of this vortex-hole duality in experiments. © 2017 American Physical Society
Development of therapeutic bioconjugates for neuroprotection in ischemic stroke.
No full textThis thesis is written based on the INRS Guide-2019, article-based version in order to fulfill the last requirement of the PhD program. It consists of an abstract (English and French versions), synopsis (required when a thesis or dissertation is written in English), general introduction, general discussion and conclusion, bibliography, and appendix which will be further discussed in below. Synopsis: Includes the main points discussed in the document and explains the working hypotheses, research objectives, methodology, and results in much more detail than the abstract does. Chapter 1: Consists of a review of literature about the ischemia, glutamate excitotoxicity, and enzymatic glutamate degradation approaches. This chapter concludes with a contextualization. Of note, some sections of this chapter are published as part of a manuscript accepted for publication in Biomaterials (Appendix C). Chapter 2: Presents concepts related to PEGylation, its benefits and its drawbacks. This chapter ends with a research proposal, the main hypothesis, and objectives. The figures used in Chapter 1 and 2 are either from the literature or made by me (with BioRender) in order to provide further explanation. Chapter 3: Published as Zaghmi, A.; Mendez-Villuendas, E.; Greschner, A. A.; Liu, J. Y.; de Haan, H. W.; Gauthier, M. A., Mechanisms of activity loss for a multi-PEGylated protein by experiment and simulation. Mater Today Chem 2019, 12, 121-131. I was responsible for data collection and analysis as well as the manuscript composition and revision. Andrea A Greschner contributed to manuscript edits and assisted with the PEGylation experiments. Jun Yang Liu was a summer student under my supervision who assisted with some measures of the enzyme activities. Eduardo Mendez-Villuendas performed the simulations with the help and supervision of Hendrick W de Haan. Marc A Gauthier was the supervisory author and was involved with concept formation, manuscript composition and revision. This Chapter starts with a brief contextualization and finishes with a preliminary study introducing the following paper. Chapter 4: Accepted as Zaghmi, A.; Dopico-López, A.; Pérez-Mato M.; Iglesias-Rey R.; Hervella P.; Greschner A. A.; Bugallo-Casal A.; Da Silva A.; Gutiérrez-Fernández M.; Castillo J.; Campos Pérez F.; Gauthier, M. A., Sustained blood glutamate scavenging enhances protection in ischemic stroke. Commun Biol 2020. I participated in the design and conception of the study, carried out most experiments (synthesis, characterisation, and purification of the bioconjugates; in vivo experiences including the functional tests). I also wrote and revised the manuscript. Antonio Dopico-López contributed with the production of the ischemic rat model. María Pérez-Mato contributed with the production of the ischemic rat model and commented on the manuscript at all stages. Ramón Iglesias-Rey and Pablo Hervella helped with technical assistance (mainly for MRI). Francisco Campos Pérez participated to the design and conception of the study, results discussion, and commented on the manuscript at all stages. Marc A. Gauthier was the supervisory author and was involved with concept formation and manuscript composition and revision. Chapter 5: General discussion, conclusion and perspectives. Summarizes the main elements of the articles and how they are related. This discussion also presents the contribution of this thesis to the field, as well as the limitations of this work. Both are framed with possible future directions that can be explored. Chapter 6: Appendix. Contains additional information to complement the body of the text and includes elements that are essential to the understanding of the thesis or to support its argumentation. It further presents scientific papers in which I am first author. - Appendix A: Supplementary information of Paper 1. - Appendix B: Supplementary information of Paper 2. - Appendix C: Review paper, accepted as Zaghmi, A.; Drouin-Ouellet J.; Brambilla, D.; and Gauthier, M. A., Treating Brain Diseases using Systemic Parenterally-administered Protein Therapeutics: Dysfunction of the Brain Barriers and Potential Strategies. Biomaterials 2020. - Appendix D: Data in Brief paper, published as Zaghmi, A.; Greschner, A. A.; Mendez Villuendas, E.; Liu, J. Y.; de Haan, H. W.; Gauthier, M. A., Determination of the degree of PEGylation of protein bioconjugates using data from proton nuclear magnetic resonance spectroscopy. Data Brief 2019, 25. - Appendix E: Book Chapter, published as Zaghmi, A.; Greschner, A. A.; Gauthier, M. A., In vivo properties of therapeutic bioconjugates composed of proteins and architecturally/functionally complex polymers. Polymer-Protein Conjugates: From PEGylation and Beyond 2020, 389-406. Chapter 7: Contains the bibliography used in this thesis. It should be noted that the references used for each scientific paper are included in this chapter (except for Appendix D and E)
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