<p>Controlling the surface chemistry of 2D materials is critical for the development of next generation applications including nanoelectronics and organic photovoltaics (OPVs). Further, next generation nanoelectronics devices require very specific 2D patterns of conductors and insulators with prescribed connectivity and repeating patterns less than 10 nm. However, both top-down and bottom-up approaches currently used lack the ability to pattern materials with sub 10-nm precision over large scales. Nevertheless, a class of monolayer chemistry offers a way to solve this problem through controlled long-range ordering with superior sub-10 nm patterning resolution. Graphene is most often functionalized noncovalently, which preserves most of its intrinsic properties (<i>i.e.,</i> electronic conductivity) and allows spatial modulation of the surface. Phospholipids such as 1,2-bis(10,12-tricsadiynoyl)-<i>sn­</i>-glycero-3-phosphoethanolamine (diyne PE) form lying down lamellar phases on graphene where both the hydrophilic head and hydrophobic tail are exposed to the interface and resemble a repeating cross section of the cell membrane. Phospholipid is made up of a complex headgroup structure and strong headgroup dipole which allows for a diverse range of chemistry and docking of objects to occur at the nonpolar membrane, these principals are equally as important at the nonpolar interface of 2D materials. A key component in the development of nanoelectronics is the integration of inorganic nanocrystals such as nanowires into materials at the wafer scale. Nanocrystals can be integrated into materials through templated growth on to surface of interest as well as through assembly processes (i.e. interfacial adsorption). </p> <p>In this work, I have demonstrated that gold nanowires (AuNWs) can be templated on striped phospholipid monolayers, which have an orientable headgroup dipoles that can order and straighten flexible 2-nm diameter AuNWs with wire lengths of ~1 µm. While AuNWs in solution experience bundling effects due to depletion attraction interactions, wires adsorb to the surface in a well separated fashion with wire-wire distances (e.g. 14 or 21 nm) matching multiples of the PE template pitch. This suggests repulsive interactions between wires upon interaction with dipole arrays on the surface. Although the reaction and templating of AuNWs is completed in a nonpolar environment (cyclohexane), the ordering of wires varies based on the hydration of the PE template in the presence of excess oleylamine, which forms hemicylindrical micelles around the hydrated headgroups protecting the polar environment. Results suggest that PE template experience membrane-mimetic dipole orientation behaviors, which in turn influences the orientation and ordering of objects in a nonpolar environment.</p> <p>Another promising material for bottom-up device applications is MoS₂substrates due to their useful electronic properties. However, being able to control the surface chemistry of different materials, like MoS₂, is relatively understudied, resulting in very limited examples of MoS₂substrates used in bottom-up approaches for nanoelectronics devices. Diyne PE templates adsorb on to MoS₂­in an edge-on conformation in which the alkyl tails stack on top of each other increasing the overall stability of the monolayer. A decrease in lateral spacing results in high local concentrations of orientable headgroups dipoles along with stacked tails which could affect the interactions and adsorption of inorganic materials (i.e. AuNW) at the interface. </p> <p>Here, I show that both diyne PE/HOPG and diyne PE/MoS₂ substrates can template AuNW of various lengths with long range ordering over areas up to 100 µm². Wires on both substrates experience repulsive interactions upon contact with the headgroup dipole arrays resulting in wire-wire distances greater than the template pitch (7 nm). As the wire length is shortened the measured distance between wires become smaller eventually resulting in tight packed ribbon phases. Wires within these ribbon phases have wire-wire distances equal to the template. Ribbon phases occur on diyne PE/HOPG substrates when the wire length is ~50 nm, whereas wire below ~600 nm produce ribbon phases on diyne PE/MoS_2­substrates. </p> <p>Another important aspect to future scientific development is the catalysis of organic reactions, specifically oxygenation of organic sulfides. Sulfide oxygenation is important for applications such as medicinal chemistry, petroleum desulfurization, and nerve agent detoxification. Both reaction rates and the use of inexpensive oxidants and catalysts are important for practical applications. Hydrogen peroxide and <i>tert</i>-butyl hydroperoxide are ideal oxidants due to being cost efficient and environmentally friendly. Hydrogen peroxide can be activated through transition metal base homogeneous catalysts. Some of the most common catalysts are homo- and hetero-polyoxometalates (POMs) due their chemical robustness. Heptamolybdate [Mo₇O₂₄]^6-is a member of the isopolymolybdate family and its ammonium salt is commercially available and low in cost.²² Heteropolyoxometalates have been widely studied as a catalyst for oxygenation reactions whereas heptamolybdate has been rarely studied in oxygenation reactions. </p> <p> Here I report sulfide oxygenation activity of both heptamolybdate and its peroxo derivate [Mo₇O₂₂(O₂)₂]^6-. Sulfide oxygenation of methyl phenyl sulfide (MPS) by H₂O₂to sulfoxide and sulfone occurs rapidly with 100 % utility of H₂O₂ in the presence of [Mo₇O₂₂(O₂)₂]^6-, suggesting the peroxo adduct is an efficient catalyst. However, heptamolybdate is a faster catalyst compared to [Mo₇O₂₂(O₂)₂]^6- for MPS oxygenation and all other sulfides tested under identical conditions. Pseudo-first order <i>k</i>_cat constants from initial rate kinetics show that [Mo₇O₂₄]^6-catalyzes sulfide oxygenation faster. The significant difference in the <i>k</i>_cat suggests differences in the active catalytic species, which was characterized by both UV-Vis and electrospray ionization mass spectrometry. ESI-MS suggest that the active intermediate of [Mo₇O₂₄]^6-under catalytic reaction conditions for sulfide oxygenation by H₂O₂ is [Mo₂O₁₁]^2-. These results show that heptamolybdate is a highly efficient catalyst for H₂O₂oxygenation of organic sulfides.</p>

L’épuisement des sources d’énergie fossile et les conséquences nocives des gaz à effet de serre sur l’environnement ont accru la nécessité de l’utilisation des énergies renouvelables. Parmi les différentes sources, la biomasse possède un potentiel considérable. Ce projet de recherche vise à étudier la pyrolyse des anas de lin et du bois de hêtre, des biomasses qui se retrouvent communément dans la région Normandie, afin de produire et d’améliorer une bio-huile capable d’être utilisée comme bio-carburant dans les moteurs à combustion. L’objet de cette thèse est donc de fournir une caractérisation détaillée des produits de la pyrolyse des deux biomasses choisies et de leurs constituants purs (la cellulose, l’hémicellulose et la lignine) dans une installation semi-continue. Un traitement catalytique de désoxygénation est ensuite employé pour améliorer les propriétés des bio-huiles obtenues. Les catalyseurs utilisés sont à base de zéolithes (HZSM-5 et H-Y), des mêmes zéolithes modifiées au fer et de métaux (Pt, CoMo) supportés sur alumine. Nous avons constaté que, dans cette installation, une pyrolyse à 500 °C, sous 500 mL/min d’azote, suivie d’une désoxygénation catalytique en utilisant Fe-HZSM-5 comme catalyseur, donnait les meilleurs résultats en termes de rendement en bio-huiles et de taux de désoxygénation. L’effet d’un changement de technologie de réacteur de pyrolyse en utilisant un réacteur continu à chute sur les produits de la pyrolyse a aussi été examiné. Ce réacteur a également été couplé à une étape de traitement catalytique de désoxygénation dans un réacteur à lit fixe indépendant. Il a été aperçu qu’en dépit d’un changement de technologie de réacteur, les conditions opératoires optimales restent les mêmes avec cependant, une différence non négligeable au niveau du taux de désoxygénation. Cette différence a été attribuée à l’effet du temps de contact. Finalement, l’efficacité du catalyseur utilisé lors de la pyrolyse en continu a été suivie dans le temps. Il a été constaté qu’au cours du temps, le catalyseur démontrait une activité décroissante, indiquant qu’un phénomène de désactivation était présent. / Depleting sources of fossil fuels and harmful consequences of greenhouse gas emissions on the environment have heightened the necessity of renewable energy resources. Among the different existing sources, biomass presents a considerable potential. This research work aimed at investigating the pyrolysis of flax shives and beech wood residues, which are biomass residues commonly found in the Normandy region, so as to produce and upgrade a bio-oil capable of being used as a bio-fuel in combustion engines. The objective of this thesis was thus to provide a detailed characterisation of the products obtained from the pyrolysis of the two chosen biomasses and their pure components (cellulose, hemicellulose and lignin) in a semi-continuous system. A catalytic de-oxygenation treatment was then employed to upgrade the properties of the bio-oils obtained. The catalysts used were zeolite-based (HZSM-5 and H-Y), the latter zeolites modified by iron and metals (Pt and CoMo) supported on alumina. It was observed that, in this setup, pyrolysis at 500 °C under 500 mL/min of nitrogen, followed by a catalytic de-oxygenation using Fe-HZSM-5 as catalyst, gave the best results in terms of bio-oil yield and de-oxygenation degree. The effect, on the pyrolysis products, of changing the pyrolysis reactor technology to a continuous drop-tube reactor was also investigated. This reactor was similarly coupled with a catalytic de-oxygenation treatment step occurring in a separate fixed bed reactor. It was found that despite a change in reactor technology, the optimal operational conditions remain the same, although a non-negligible difference was noticed with respect to the de-oxygenation degree. This difference was attributed to the effect of contact time. Finally, the efficiency of the catalyst used during the continuous pyrolysis was monitored in time. It was seen that over time, the catalyst presented a diminishing activity, indicating the presence of a de-activation phenomenon.

L’ischémie est une des problématiques majeurs de la transplantation, elle intervient au moment de la déconnexion d’un organe du système vasculaire et dure jusqu’à sa reconnexion chez le receveur. Elle provoque une diminution de la qualité des greffons et seulement un-tiers des pancréas éligibles aboutissent à une transplantation. Ce travail de thèse avait pour objectif d’améliorer la qualité des greffons en préparant les pancréas à subir l’ischémie par le préconditionnement et à améliorer leur préservation après avoir identifié les voies impliquées dans l’ischémie. Des changements métaboliques majeurs au niveau de l’organe ont été mis en évidence dépendant du temps d’ischémie, impliquant des dommages sur la partie endocrine du pancréas, les îlots. Ceci a été empêché par le préconditionnement du pancréas à l’ischémie activant les défenses antioxydantes et par l’utilisation de l’hémoglobine M101 issue de ver marin apportant de l’oxygène au cours de la préservation des pancréas de rat et humains. Ainsi, il est possible d’améliorer la qualité des greffons en agissant en amont du prélèvement et au cours de la préservation, ceci permettant une meilleure fonction. / Ischemia is one of the major problems of transplantation, it occurs at the time of disconnection of an organ of the vascular system and lasts until its reconnection in the recipient. It causes a decrease in graft quality and only one-third of the eligible pancreases results in a transplant. This work aimed to improve the quality of the grafts in preparing the pancreas to undergo ischemia preconditioning and improve their preservation after identifying the pathways involved in ischemia. Major metabolic changes in the organ have been demonstrated that appeared to ischemia time dependent enhancing damages to the endocrine part of the pancreas, the islets. This was prevented by the preconditioning of the pancreas to ischemia activating the antioxidant defenses and by the use of the marine worm M101 hemoglobin providing oxygen during the preservation of rat pancreas and humans. Thus, it is possible to improve the quality of the grafts by acting upstream of the sample and during the preservation, this allowing a better function.

Current Possibilities in Use of a Centrifugal Pump in the Cardiac Sugery Abstract Currently, the most commonly used technical solution for pumping blood during extracorporeal circulation during cardiac surgery, as well as for some types of ECMO (extracorporeal membrane oxygenation) are either a roller pump or centrifugal pump. Due to its advantages the centrifugal pump is mainly used for prolonged extracorporeal circulation in cardiac surgery and as a heart and / or lung support system. In current literature there is a lack of compelling scientific evidence that would clearly support its use in a routine cardiac surgery. The aim of our study was to compare both types of currently used blood pumps in longer cardiac procedures with deep hypothermic circulation arrest. In a randomized clinical study we had selected a group of patients that underwent a pulmonary endarterectomy (PEA) in order to demonstrate the positive effects of the centrifugal pump on the postoperative inflammatory reactions. There were no statistically significant differences between these two pumps when other clinical and laboratory parameters were observed. Based on the hypothesis that significant temperature changes during cardiac procedure with a deep hypothermia can affect sealing pressure of the endotracheal tube cuff, we performed a...

Current Possibilities in Use of a Centrifugal Pump in the Cardiac Sugery Abstract Currently, the most commonly used technical solution for pumping blood during extracorporeal circulation during cardiac surgery, as well as for some types of ECMO (extracorporeal membrane oxygenation) are either a roller pump or centrifugal pump. Due to its advantages the centrifugal pump is mainly used for prolonged extracorporeal circulation in cardiac surgery and as a heart and / or lung support system. In current literature there is a lack of compelling scientific evidence that would clearly support its use in a routine cardiac surgery. The aim of our study was to compare both types of currently used blood pumps in longer cardiac procedures with deep hypothermic circulation arrest. In a randomized clinical study we had selected a group of patients that underwent a pulmonary endarterectomy (PEA) in order to demonstrate the positive effects of the centrifugal pump on the postoperative inflammatory reactions. There were no statistically significant differences between these two pumps when other clinical and laboratory parameters were observed. Based on the hypothesis that significant temperature changes during cardiac procedure with a deep hypothermia can affect sealing pressure of the endotracheal tube cuff, we performed a...

Title: Application of blood flow restriction by a sport training of climbers - an innovative training method for sportsmen? Author: Tomáš Javorský BSc. Department: Department of Physiology Supervisor: doc. Jiří Baláš, Ph.D. Abstract: The most common injuries of performance climbers include tendon injuries of finger flexors. This kind of injury can leave a sportsman unable to follow his training programme for several months, which can have a crucial impact on his peak season. The thesis comprised a comparison of a high-intensity training performed at 70% of muscle strength maximum, with a blood flow restriction training performed at a 30% muscle load, and also the physiological and functional aspects of the training. Objectives: The presumption is, that the combination of a low muscle load with an ischemy will achieve the same results as a high-intensity training. We also presume, that the alterations in muscle oxygenation remain the same despite different amounts of performed muscle work. Methods: 13 participants finished the experiment performed in the form of a crossover study. During the experiment the muscle oxidative capacity and the extent of the muscle deoxygenation were measured by spectroscopy. The maximum force, critical force, impulse and the impulse above the critical force point were measured...

Introduction: Left-ventricular (LV) distension and consequent pulmonary congestion are complications frequently discussed in patients with severe LV dysfunction treated with veno- arterial extracorporeal membrane oxygenation (VA ECMO). The goal of this study was to describe the influence of high VA ECMO flows to LV distension, lung hemodynamics, and lung fluid accumulation. Methods of LV decompression were studied to prevent lung edema. Methods: In all experiments porcine models under general anesthesia were used. The effects of high extracorporeal blood flow (EBF) on LV heart work were assessed in a chronic heart failure model. The effects of LV afterload on lung fluid accumulation were evaluated by electrical impedance tomography (EIT) on acute heart failure models. Phase and frequency filtration and mathematical analysis were applied to the raw EIT data. Subsequently, mini- invasive techniques of LV decompression were evaluated for LV work. Results: The stepwise increases of VA ECMO flow improved both hemodynamic and oxygenation parameters. Nevertheless, it also caused distension and increased work of LV. The rise in EBF led to increased pulmonary capillary wedge pressure and lung fluid accumulation assessed by EIT in heart failure. The methods for LV decompression (Impella pump, atrial...

Aim: To examine local muscle oxygen kinetics when performing wrist extensions till failure in an occluded versus non-occluded state, to compare the perceived ratings of pain and local muscle exertion, and analysing presence of gender differences. Methods: Twenty-one healthy individuals (mean age 25,6±3.2, 10 females) performed wrist extensions at 30% of peak isometric strength till failure. The order in which the states was performed was randomized. The oxygen kinetics in the m. extensor digitorum was analysed using Near-infrared spectroscopy continuously. Ratings of perceived pain and local muscle exertion were collected before exercise, when reaching failure and post exercise recovery. Result: No difference was identified in tissue oxygen saturation (TOI) at the exercise plateau (-24.0±18.3% vs -23.5±13.9%, p=0.609). TOI at rest was lower for the occluded state (64.2±4.5% vs 57.2±5.9%, p&lt;0.001). During the second minute of recovery, there was a greater increase in TOI for the occluded state (0.01±0.01%/sec vs 0.04±0.03/sec, p&lt;0.001). A higher rating of perceived pain was found for the occluded state during baseline (0.0±0.0 vs 0.7±0.9, p=0.005) and first minute of recovery post exercise (2.3±2.0 vs 3.3±2.1, p=0.011). No clinically relevant gender differences were found. Conclusion: Venous occlusion during low-intensity dynamic wrist extensions affects the local oxygen kinetics in the muscle before and after exercise. The oxygenation kinetics does not differ when exercise plateau is reached when both regimes are performed till failure. This suggests that performing low-load dynamic wrist extensions in a no-relaxation manner, may have the same effects no matter whether occlusion is used or not. / Syfte: Att undersöka den lokala syreomsättningen i muskeln när handledsextensioner utförs till failure i ockluderat tillstånd jämfört med icke-ockluderat tillstånd, samt att jämföra den skattade upplevda smärtan och lokala muskelansträngningen, och eventuella skillnader mellan könen. Metod: Tjugoen friska individer (medelålder 25.6±3.2, 10 kvinnor) utförde handledsextentioner på 30 % av maximal isometrisk styrka till failure. Ordningen av ocklusion och icke-ocklusion var randomiserad. Nära-infraröd spektroskopi användes för att undersöka syreomsättningen lokalt i m. extensor digitorum. Skattning av upplevd smärta och lokal muskelansträngning samlades in före träning, vid failure och vid återhämtning efter träning. Resultat: Ingen skillnad identifierades i vävnadssyremättnad (TOI) vid uppnådd träningsplatå (-24.0±18.3% vs -23.5±13.9%, p=0.609). TOI i vila var lägre för det ockluderade tillståndet (64.2±4.5% vs 57.2±5.9%, p &lt;0.001). Under den andra återhämtningsminuten var det en större ökning av TOI för det ockluderade tillståndet (0.01±0.01%/sek vs 0.04±0.03/sek, p &lt;0.001). En högre skattning av upplevd smärta sågs för det ockluderade tillståndet under den första vilominuten (0.0±0.0 vs 0.7±0.9, p=0.005) och första minuten av återhämtning (2.3±2.0 vs 3.3±2.1, p=0.011). Inga kliniskt relevanta skillnader mellan könen hittades. Slutsats: Ocklusion under lågintensiva dynamiska handledsextensioner påverkar den lokala syreomsättningen i muskeln före och efter träning. Den muskulära syreomsättningen skiljer sig däremot inte när träningsplatå uppnås när båda regimerna utförs till failure. Detta tyder på att utförande av dynamiska handledsextensioner på låg belastning utan att muskeln tillåts att slappna av, kan ge samma effekter oberoende av om ocklusion appliceras eller inte.

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