Natural products have been demonstrated to be of great significance to the pharmaceutical industry in the development of new drugs and medicine. Unfortunately, synthetic approaches to obtain these natural products often prove increasingly challenging due to the complexity of synthesizing the target drug in the proper stereochemistry. The availability of enantioselective reactions can play a pivotal role in overcoming this challenge, yielding access to optically pure intermediates and products. Chiral ligands based on a trans-1,2-diaminocyclohexane motif are often employed for this purpose and their complexes with transition metals have been demonstrated to act as efficient chiral catalysts in asymmetric reactions. In contrast, studies involving cis-1,2-diaminocyclohexane derivatives as chiral catalysts are strongly underrepresented. We have designed and performed the synthesis of an axially chiral conformationally locked cis-1,2-diamine scaffold, conveniently designed for further derivatization into more complex structures. A key step in this synthesis was the chiral resolution of a racemic intermediate, realized through both chemical and enzymatic means in a comparative study. Utilizing the newly gained optically pure primary diamine scaffold, a library of chemically diverse secondary diamine ligands has been synthesized and characterized through NMR spectroscopy, mass spectrometry, and chiral HPLC. Assignment of the absolute configuration within the cis-1,2-diamine scaffold was realized through single-crystal X-ray crystallography experiments on one of the synthetic intermediates. The synthesized ligands have been evaluated for their potential to function as chiral catalysts in the asymmetric Henry reaction and asymmetric transfer hydrogenation. As a function of both steric and electronic structural variation, a range of catalytic activities and enantioselectivities in the Henry reaction were observed. The ligands proved to be less suitable for asymmetric transfer hydrogenation with only a select number of ligands catalyzing the reaction, and a single example resulting in a decent enantioselectivity. We additionally explored the possibility of incorporating a chemical switch into the scaffold, responsible for switching the axial chirality of the molecule. As a consequence of inverting the axial chirality, the configuration of the potential reaction product in asymmetric synthesis would also be inverted. To this extent, we performed the synthesis of a novel specifically designed crown ether, dicyclohexeno-18-crown-6, furnished with two π-bonds in the cyclohexane rings, allowing for additional modification into more advanced functionalized structures.

Objectifs: Le but principal de cette étude prospective multicentrique est d’évaluer les succès clinique et radiographique des pulpotomies avec la Biodentine sur des dents permanentes traumatisées avec exposition pulpaire. Les objectifs secondaires sont d’évaluer si la maturation radiculaire affecte le pronostic du traitement et si la Biodentine cause une décoloration significative de la structure dentaire. Matériel et Méthode: Cette étude a été réalisée dans deux centres hospitaliers universitaires au Canada. Des sujets de moins de 18 ans se présentant avec un traumatisme sur les dents permanentes antérieures ont été invités à participer à cette étude. Les sujets médicalement compromis ainsi que les dents associées à une avulsion ont été exclus. La collecte de données comprenait: les données démographiques des patients, la durée et la taille de l'exposition pulpaire, le traumatisme associé et le stade de maturation radiculaire. Les cas ont été suivis jusqu’à 24 mois post-traitement. Les critères de succès clinique étaient l’absence de symptômes, des tests de vitalités positifs et un sondage normal. Le succès radiologique a été déterminé comme suit: continuation de la maturation radiculaire (apexogenèse) des dents immatures et apparence normale des tissus périradiculaires. Résultats: Quarante-cinq patients, dont 25 hommes et 20 femmes, âgés entre 8 et 16 ans (moyenne 10,86 ± 2,2) ont été inclus dans cette étude. Au total, 51 dents ont été traitées dont 29 dents immatures. Six dents traitées ont été perdues aux suivis et la période de suivi moyenne était de 13 mois (6-24). Les résultats ont montré un taux de survie de 100% et un taux de réussite de 91%. Quatre échecs ont été notés, deux à un mois et les deux autres à sept et 15 mois. Les résultats cliniques ont montré une diminution des symptômes et une augmentation de la positivité des tests de vitalité avec le temps. Huit dents ont présenté une légère décoloration, mais restaient esthétiquement acceptable. Les résultats radiologiques ont montré une formation de ponts dentinaires dans 90% des cas et toutes les dents immatures ont montré une continuation de la maturation radiculaire. Conclusions: Les pulpotomies à la Biodentine ont montré un taux de succès élevé sur des dents antérieures permanentes avec expositions pulpaires traumatiques avec un suivi moyen de 13 mois. Nos résultats montrent que la Biodentine peut constituer une alternative à l’hydroxyde de calcium et au Mineral Trioxide Aggregate et n’entraine pas une décoloration significative de la dent. Finalement, le stade de maturation radiculaire n’a pas affecté le pronostic du traitement. Mots-clés : Pulpotomie, thérapie pulpaire vitale, fracture coronaire avec exposition pulpaire, Biodentine. / Objectives: The aim of this multicentric prospective study was to evaluate the clinical and radiographic outcomes of Biodentine pulpotomies on permanent traumatised teeth with pulp exposure. The secondary objectives were to evaluate if root maturation affects the treatment outcome and to assess color stability of Biodentine. Methods: This study was carried out in two hospital-based dental departments in Canada. Children seeking emergency care following trauma to anterior permanent teeth were invited to participate in this study. Medically compromised children and teeth with concomitant avulsion were excluded. Data collected included: patient demographics, time since pulp exposure, size of exposure, associated trauma and radiographic root maturation stage. The treatment outcome was assessed clinically and radiographically up to 24 months after treatment. Clinical success was determined when a tooth remained asymptomatic and when it responded positively to vitality testing with normal probing. Radiographic success was determined as follow: continuation of root maturation (apexogenesis) in immature teeth and normal appearance of periradicular tissues. Results: Forty-five patients between the age of 8 to 16 years old (mean 10.86 ± 2.2) were included in this study. There were 25 males and 20 females. A total of 51 teeth were treated with a Biodentine pulpotomy of which twenty-nine (57%) had an immature apex. Six teeth were lost to follow-up. The average follow-up period was 13 months (6-24). This study showed a survival rate of 100% and a success rate of 91%. Four failures were noted, two at one month and the others at seven and 15 months post- treatment. Clinical outcomes showed that, over time, tooth sensitivity decreased whereas positive vitality testing increased. Eight teeth showed slight discoloration, however the results remained esthetically satisfying. Radiographic outcomes showed dentinal bridge formation in 90% of cases. All immature teeth showed continued root formation. Conclusions: Biodentine pulpotomies showed a high success rate on anterior permanent traumatized teeth with a pulp exposure at 13 months follow-up. According to our results, Biodentine may be a good alternative to calcium hydroxide and Mineral Trioxide Aggregate vital pulpotomies and did not cause significant discoloration. Finally, root maturation did not affect the treatment outcome. Keywords: Complicated crown fractures, pulpotomy, vital pulp therapy, Biodentine.

Les modèles structure-fonction de la croissance des plantes (FSPMs) combinent la description du fonctionnement biophysique et du développement architectural des plantes. On peut distinguer deux grandes familles de FSPM : d'une part les modèles décrivant finement la structure de la plante au niveau de l'organe et d'autre part les modèles à plus grande échelle qui s'intéressent directement à la forme du houppier. La paramétrisation du premier type de modèle est souvent difficile car elle nécessite des données expérimentales très riches. A l'inverse, les modèles à plus grande échelle mettent généralement en œuvre des lois empiriques qui ne permettent pas de décrire la plasticité de la croissance, et l'adaptation de la plante à des conditions environnementales différentes.Pour répondre à ces problématiques, nous nous tournons vers un nouveau paradigme : Motivé par le succès du concept de la densité spatiale dans les modèles en écologie des populations, cette thèse caractérise la distribution spatiale de feuillage dans les plantes par la densité de surface foliaire , ce qui permet une description locale ouvrant la voie à une prise en compte de la plasticité des plantes, tout en ne décrivant pas chaque feuille individuellement, ce qui permet de modéliser des vieux et grands arbres, dont le nombre de feuilles est sinon trop lourd à gérer du point de vue des calculs. Cette thèse présente des modèles dynamiques de croissance développés spécifiquement pour les plantes agricoles et les arbres. Nous explorons des approches mathématiques différentes en temps discrète et continue, tout en examinant d'un œil critique leurs aptitudes conceptuelles ainsi que des possibilités de simplifications et de solutions analytiques dans l'optique de l'accélération des simulations.La densité foliaire permet le calcul de l'interception de lumière par la loi de Beer-Lambert et la production de biomasse grâce au concept d'efficience d'utilisation de la lumière. Le mécanisme central qui est considéré pour les différentes approches développées dans cette thèse est celui de l'expansion locale de la surface foliaire dans la direction du gradient de lumière. Par ce concept téléonomique, nous faisons l'hypothèse que la plante cherche par son développement à optimiser la productivité de la surface foliaire pour la production de biomasse. Ce principe induit ainsi un développement horizontal et vertical du feuillage vers l'extérieur du houppier. Le développement horizontal cesse quand on s'approche trop de plantes voisines, leur ombrage diminuant le gradient de lumière et donc l'expansion de densité de surface foliaire dans ces directions. Le modèle de production de biomasse est également généralisé pour une prise en compte explicite de la teneur en eau du sol en introduisant une composante hydraulique permettant de décrire l'équilibre mécaniste entre le potentiel hydrique dans les feuilles et la transpiration par la régulation stomatale. Finalement, nous prenons en compte l'allocation de biomasse produite à d'autres compartiments de la plante tels que les racines et le bois selon la théorie du « pipe model ».Les résultats des modèles sont comparés à un large jeu de données expérimentales sur des plantations à différentes densités et conditions environnementales. Celui-ci montre de remarquables capacités d'une part à prévoir les variables biométriques importantes (hauteur, diamètre du tronc) ainsi que certaines relations d'allométrie, et d'autre part à générer des formes de houppier en accord avec les formes observées, ceci pour les différents scénarios de compétition et comme propriété émergente du modèle. Ainsi, cette thèse démontre le potentiel du concept de densité de surface foliaire en modélisation de la croissance des plantes, par sa capacité à reproduire les comportements locaux et l'adaptation à des conditions environnementales variées sans compromettre l'efficacité et la robustesse. / Functional-structural plant growth models (FSPMs) have emerged as the synthesis of mechanistic process-based models, and geometry-focussed architectural models. In terms of spatial scale, these models can essentially be divided into small-scale models featuring a topologic­al architecture – often facing data-demanding parametrisations, parameter sensitivity, as well as computational heaviness, which imposes problematic limits to the age and size of in­dividuals than can be simulated – and large-scale models based on a description of crown shape in terms of rigid structures such as empirical crown envelopes – commonly strug­gling to allow for spatial variability and plasticity in crown structure and shape in response to local biotic or abiotic growth conditions.In response to these limitations, and motivated not least by the success-story of spatial density approaches in theoretical populations ecology, the spatial distribution of foliage in plants in this thesis is characterised in terms of spatial leaf density, which allows for a com­pletely local description that is a priori unrestricted in terms of plasticity, while being robust and computationally efficient. The thesis presents dynamic growth models specific­ally developed for crops and trees, exploring different mathematical frameworks in continu­ous and discrete time, while critically discussing their conceptual suitability and exploring analyt­ical simplifications and solutions to accelerate simulations.The law of Beer-Lambert on the passing of light though an absorbing medium allows to infer the local light conditions based on which local biomass production can be computed via a radiation use efficiency. A key unifying mechanism of the different models is the local ex­pansion of leaf density in the direction of the light gradient, which coincides with the direc­tion most promising with regard to future biomass productivity. This aspect falls into the line of teleonomic and optimization-oriented plant growth models, and allows to set aside the otherwise complex modelling of branching processes. The principle induces an expans­ive horizontal and upward-directed motion of foliage. Moreover, it mechanistically accounts for a slow-down of the horizontal expansion as soon as a neighbouring competitor's crown is reached, since the appropriate region is already shaded, implying a corresponding adapta­tion of the light gradient. This automatically results in narrower crowns in scenarios of in­creased competition, ultimately decreasing biomass production and future growth due to lesser amount of intercepted light. In an extension, the impact of water availability is incor­porated into the previously light-only dependency of biomass production by means of a novel hydraulic model describing the mechanistic balancing of leaf water potential and tran­spiration in the context of stomatal control. The allocation of produced biomass to other plant compartments such as roots and above-ground wood, e.g. by means of the pipe model theory, is readily coupled to leaf density dynamics.Simulation results are compared against a variety of empirical observations, ranging from long-term forest inventory data to laser-recorded spatial data, covering multiple abi­otic environmental conditions and growth resources as well as stand densities and thus de­grees of competition. The models generate a series of complex emergent properties includ­ing the realistic prediction of biometric growth parameters, the spontaneous adaptability and plasticity of crown morphologies in different competitive scenarios, the empirically documented insensitivity of height to stand density, the accurate deceleration of height growth, as well as popular allometric relationships – altogether demonstrating the potential of leaf density based approaches for efficient and robust plant growth modelling.

Indiana University-Purdue University Indianapolis (IUPUI) / Introduction: Some intracanal medicaments used in regenerative endodontics may compromise the bond strength of root cements and lead to tooth discoloration. Objectives: To evaluate the effects of 1) low concentrations of TAP and DAP (1 mg/mL) on push-out bond strength of various root cements, and 2) low concentrations of TAP and DAP (1 mg/mL and 10 mg/mL) on crown discoloration. Materials and Methods: Single rooted human teeth (n = 144) were horizontally decoronated and instrumented according to standardized protocol. The samples were randomized into six experimental groups (Ca(OH)2, 1000 mg/mL TAP and DAP, 1 mg/mL TAP and DAP, and no medicament control group. After four weeks, the medicaments were removed and each group was divided into three subgroups to receive MTA cement, Biodentine cement, or Endosequence Bioceramic putty cement for two weeks. Then, two root cylinders were obtained from each root and push-out bond strength testing was performed. For the crown discoloration experiment, 160 crowns were obtained from intact human molars and randomized into experimental groups as described earlier with the addition of two groups (10 mg/mL TAP and DAP). The pulp chambers in half of the samples from each group were coated with an adhesive bonding agent before receiving the assigned intracanal medicament. Color changes (ΔE) were detected by spectrophotometer at 1 day, 1 week, and 4 weeks after application, as well as after thermocycling. Results: In the push-out bond strength experiment, 1 mg/mL DAP generally demonstrated significantly higher bond strength of root cements compared with the other treatment groups. For the crown discoloration experiment, when an adhesive bonding agent was used prior to (10 mg/mL or 1000 mg/mL) TAP, the crowns had significantly less discoloration than those without adhesive. DAP 10 mg/mL had the least significant color change at all time points regardless of whether adhesive was used. Conclusion: 1) 1 mg/mL DAP and Ca(OH)2 did not have significant negative effect on the bond strength of calcium-silicate-based cement to radicular dentin. 2) 1 mg/mL and 10 mg/mL of DAP and Ca(OH)2 had significantly less effect on the color change of the human tooth crown than all intracanal medicaments used in this study. / 2020-08-13

Hardening distortions are unwanted changes in shape and dimension that arise during hardening of steel components. Uncontrolled distortions induce random errors to the manufacturing process, and have a strong negative impact on manufacturing costs. The distortions are not only caused by the hardening process, several factors from previous manufacturing steps including the component geometry itself contribute to varying extent. The aim of the current work is to investigate the main influencing factors on hardening distortions for serial produced gears. The investigations were done on two different types of gears for heavy-duty transmissions, crown wheels for the rear axle central gear and main shaft gears for the gearbox. The steel was produced using either continuous casting or ingot casting. For rectangular continuously cast steel, the effect of disabling magnetic stirring of the steel melt during casting was investigated, finding a strong reduction of gear runout for crown wheels. Segregations in crown wheels produced from the top and bottom of ingots were shown to go in opposite directions, producing opposite back-face tilts. For crown wheels quenched one at a time, influences of stacking level on the hardening tray were found, indicating an impact from small variations in the carburizing process, despite identical quenching conditions. For main shaft gears, horizontal loading gave considerably less roundness and runout errors but increased flatness errors compared to vertical loading. This thesis shows the complexity of the distortion phenomenon and how several factors interact and contribute to the final result. It is shown that factors with significant impact on hardening distortions for one component may be less important for another component. With this in mind, each type of component to be hardened should be produced by a manufacturing chain where each process step is carefully chosen with respect to minimizing distortions. / <p>QC 20170516</p>

No description available.

No description available.

Syfte:Syftet med föreliggande studie var att utvärdera kliniskt lyckande, överlevnad och misslyckande för metal-keramiska singelkronor och broar med underkonstruktion av titan som lämnats ut till patienter på Odontologiska fakulteten, Malmö högskola. Material och metod:För att svara på den aktuella frågeställningen identifierades patienter som mellan åren 2011-2015 fått fastsittande protetiska konstruktioner i titan-keramik, på Odontologiska fakulteten, Malmö högskola. Patienterna undersöktes av två tandläkarstudenter, under deras åttonde termin (april 2016), med visuell-taktil metod. Resultat:47 stycken patienter ingick i studien, detta motsvarade 69% av alla patienter som matchade inklusions - och exklusionskriterierna. Hos dessa 47 patienter fanns totalt 67 konstruktioner med en medelålder på 35 månader och en medianålder på 29 månader. Av de inkluderade konstruktionerna var 47 stycken singelkronor och 20 broar. Den kliniska lyckande, överlevnad och misslyckande frekvensen för singelkronorna var 55%, 43% och 2%, medan den för broarna var 15%, 70% och 15%. Slutsats:Inom studiens begränsningar har följande slutsatser dragits: •De titan-keramiska singelkronorna utlämnade till patienter på Odontologiska fakulteten, Malmö högskola, hade en högre lyckandefrekvens än de titan-keramiska broarna.•Resultatet indikerade en övergripande hög lyckande- och överlevnadsfrekvens för titan-keramiska konstruktioner. / Aim:The aim of this study was to evaluate the clinical success, survival and failure rate of titanium-ceramic single crowns (SCs) and fixed dental prostheses (FDPs) submitted to patients at the Faculty of Odontology, Malmö University. Materials and Method:To answer the research question, patients with SCs and/or FDPs made in titanium-ceramic at the Faculty of Odontology, Malmö University, between year 2011-2015, were identified and later examined by, two dental students during their eight semester (April 2016), with a visual-tactile method. Results:The study contained a total of 47 participating patients, this outcome represented 69 % of all the patients found matching the inclusion and exclusion criteria during the patient selection. Out of the 47 participants, 67 restorations were obtained and examined. The 67 restorations that were included in the study had a mean age of 35 months and a median age of 29 months. Out of these, 47 were SCs and 20 were FDPs. The clinical success, survival and failure rate of the SCs were 55%, 43% and 2%, respectively. The clinical success, survival and failure rate of the FDPs were 15%, 70% and 15%, respectively. Conclusion:Within limits of this study the following conclusions were made:•The titan-ceramic SCs submitted to patients at the Faculty of Odontology, Malmö University had a higher success rate compared to the FDPs.•The results indicate an overall high and acceptable success and survival rate for the titan-ceramic restorations.

During the last 10 years, low pressure carburizing and high pressure gas quenching has become more popular since it is a “new” process and researchers reports that the distortion characteristics gained from these processes is improved in relation to conventional processes. The aim of this work was to investigate the distortions gained from three different heat treatment processes on main shaft gears and crown wheels. Experiments with atmospheric carburization with oil quenching and low pressure carburization with nitrogen gas quenching or oil quenching were made and distortion characteristics gained from these processes were then measured and compared. It was found that components treaded in the relatively new LPC-HPGQ process are similar and often even better than the conventional method. The larger main shaft gear improves the most with newer method but instead gets a lower core hardness and systematic diametrical shrinkage. Some measurements on the crown wheel were also improved but others were affected negatively.

Design and preparation of novel host/guest systems, such as pseudorotaxanes, semirotaxanes, rotaxanes and catenanes, with high association constants, enhanced yields and the abilities to respond to external stimuli are of great importance and significance due to their topological novelty and potential application. The convergence of supramolecular chemistry with polymer science provides an important way to extend the scope of polymer and material sciences by incorporating designed host/guest systems into polymers, and the resulting non-covalently linked supramolecular polymers are expected to have unusual properties due to their unique architectures compared with traditional polymers. After discovery of bis(meta-phenylene)-32-crown-10 (BMP32C10) derivative/paraquat complexes, for about a quarter century only “taco”-shaped complexes were observed by X-ray crystallography. Here, by the self-assembly of a BMP32C10 bearing two electron-donating groups (carbazoles) with electron-accepting paraquat derivatives, the first [2]pseudorotaxane and the first pseudocryptand-type poly[2]pseudorotaxane based on BMP32C10 were isolated as crystalline solids as shown by X-ray analyses. The first dual component pseudocryptand-type [2]pseudorotaxanes were designed and prepared via the self-assembly of synthetically easily accessible BMP32C10 pyridyl, quinolyl and naphthyridyl derivatives with paraquat. The formation of the pseudocryptand structures in the complexes remarkably improved the association constants by forming the third pseudo-bridge via H-bonding with the guest and π-stacking of the heterocyclic units. A pseudocryptand-type [2]pseudorotaxane was formed via the self-assembly of a dipyridyl BMP32C10 derivative and a paraquat derivative. Due to the basicity of the pyridyl group, which forms the third pseudo-bridge of the pseudocryptand, this pseudorotaxane represents the first system with acid-base adjustable association constants, i. e., finite both under acidic and neutral conditions. The first pseudocryptand-type supramolecular [3]pseudorotaxane was designed and prepared via the self-assembly of a bispicolinate BMP32C10 derivative and a bisparaquat. The complexation behavior was cooperative. In addition, the complex comprised of the BMP32C10 derivative and a cyclic bisparaquat demonstrated strong binding; interestingly, a poly[2]pseudocatenane structure was formed in the solid state for the first time. Two novel BMP32C10 cryptands, bearing covalent and metal complex linkages, were designed and prepared. By employing the self-assembly of these biscryptands, which can be viewed as AA monomers, and a bisparaquat, which can be viewed as a BB monomer, the first AA/BB-type linear supramolecular polymers with relatively high molecular weights were successfully prepared. Via the self-assembly of two BMP32C10-based cryptands, bearing covalent and metal complex (ferrocene) linkages, with dimethyl paraquat, novel [3]pseudorotaxanes were formed statistically and anticooperatively, respectively. From a hydroxyl-functionalized secondary ammonium salt a [2]semirotaxane and a [2]rotaxane were prepared successfully with dibenzo-24-crown-8 (DB24C8). X-ray analysis of a single crystal of the [2]semirotaxane confirmed its semirotaxane nature. In addition, the formation of the [2]semirotaxane can be reversibly controlled by adding KPF6 and 18C6 sequentially. This system affords a way to prepare novel supramolecular polymers. Dibenzo-30-crown-10 (DB30C10) derivatives and pyridine-based DB30C10 cryptands were prepared by employing the templating method established by our group. A [2]pseudorotaxane was prepared based on DB30C10 diol and paraquat diol. The [3]pseudorotaxane formed via the self-assembly between DB30C10 cryptand and bisparaquat diol occurred in a cooperative manner. In addition, a bromo-functionalized DB30C10 cryptand was successfully designed and prepared. An alkyne-functionalized DB30C10 cryptand was designed and is under preparation; its precursors have been prepared successfully. In the future, based on these functionalized cryptands and paraquat salts, AA and AB type monomers will be prepared. Via the self-assembly between these monomers, non-covalent supramolecular polymers with high molecular weight will be afforded. A novel DB30C10 cryptand bearing an organometallic bridge, ferrocene, was prepared via 1-(3'-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDCI) coupling of the crown ether diol with ferrocene dicarboxylic acid. The cryptand is dimerized in the solid state via π, π-stacking and hydrogen bonds. The ferrocene-based cryptand formed novel [2]pseudorotaxanes with paraquat and diquat PF₆ salts with association constants (Kₐ) of 1.7 ± 0.1 x 10³ and 4.2 ± 0.3 x 10⁴ M⁻¹ in acetone-d₆, respectively. In order to prepare linear polycatenanes, the preparation of which represent a real synthetic challenge, a series phenanthroline derivatives were designed and prepared. A “U” shaped monomer was successfully prepared in relative high yield with good solubility. In the future, real linear polycatenanes will be prepared. In addition, a novel diphenanthroline-based BMP32C10 derivative was prepared in high yield and the complexation behavior between it and dimethyl paraquat was studied. / Ph. D.