This diploma thesis was focused on the preparation and characterization of biodegradable composites based on poly-3-hydroxybutyrate (PHB) and spent coffee grounds (SCG). The aim was to prepare biocomposites based on PHB and coffee grounds. Biocomposites were prepared by solution casting in chloroform. Films with a thickness of about 150-200 µm were prepared with the addition of 20% unmodified and modified coffee grounds. The PHB/SCG films were modified by an addition of a plasticizer and a crosslinking agent or by blending with polybutylene adipate terephthalate (PBAT). The thermal properties of the films were determined by differential scanning calorimetry. The compatibility filler/polymer matrix compatibility was assessed morphologically with the naked eye. It has been found that the direct addition of spent coffee grounds to the PHB is not suitable due to the deterioration of the morphology of the film surfaces and the formation of aggregates. The compatibility between the spent coffee grounds and the PHB was improved after the addition of the plasticizer and the crosslinking agent. However, the highest compatibility between SCG and PHB was achieved in the case of esterified coffee grounds. Another way to improve the resulting morphological properties of the films thus prepared was to use coffee grounds fractions.

The vitamin B3 precursor nicotinamide riboside (NR) and the ketone DL-body beta-hydroxybutyrate (BHB) are two of the most promising natural compounds yet identified for the treatment of aging and aging-related diseases. NR increases nicotinamide adenine dinucleotide (NAD) levels to activate sirtuin protein deacetylases and BHB is an anti-aging calorie restriction (CR) mimetic. Caenorhabditis elegans is a 1 mm long nematode worm used as a model system to study aging with a mean lifespan of roughly 2-3 weeks depending upon the exact temperature of culture. NR and BHB have previously been shown to increase lifespan when administered to C. elegans by roughly 20%. However, the effect on lifespan when both compounds are added together has not yet been studied. It is hypothesized that when added together the effect on lifespan will be slightly larger than when either compound is given alone, due to the activation of complementary signaling pathways. The results will help determine if humans could benefit from taking both compounds simultaneously as most signaling pathways that regulate lifespan are conserved from nematodes to humans. For these experiments cultures of mixed age C. elegans nematodes were first treated with alkaline-bleach to kill adult worms leaving only eggs that are protected by their thick eggshell. Using this protocol isolated eggs are age-synchronized to within 9 hours of each other. The eggs were then transferred into E. coli-permeable, but nematode impermeable 8 micron cell culture inserts placed in twelve well microplates with roughly 25-40 eggs per insert. 1.35 mL of liquid S-media containing 9 x109 E. coli cells/mL as food was added to each well. Microplates were shaken to provide culture aeration. After three days, the worms reached adulthood and 0.4 mM fluorodeoxyuridine (FUdR), a DNA synthesis inhibitor, was added to prevent C. elegans egg-laying to maintain age-synchrony. Every Monday, Wednesday, and Friday for the approximate 4 weeks of the lifespan experiments the worms were counted under a microscope and the culture media and bacteria replaced. Results were analyzed using Kaplan-Meier survival curves and Log-rank analysis. Results indicated that individual treatment with BHB or NR or both combined increased lifespan in the two trials performed thus far. Another trial is currently underway, and results will be analyzed after it is completed to determine if the combined treatment has a greater benefit on lifespan then either individual treatment. Future studies could also be performed to determine if either NR or BHB can further extend the lifespan of animals given rapamycin, a TOR kinase inhibitor, another promising anti-aging therapeutic.

Elevated ketone production and utilization results in a host of health benefits. The aim of this study was to assess the rate of ketone production during a prolonged fast and to evaluate how an initial bout of exercise influences this production. Mood and hunger, along with plasma insulin and glucagon, were also assessed. In this crossover study, 20 adult subjects (11 Male, 9 Female) completed two 36-hour fasts, with one protocol requiring the subject to complete an intense treadmill exercise session at the beginning of the fast. Ketone levels were assessed via blood ketone meter and recorded every two hours. Subjective mood and hunger ratings were also recorded every two hours. Venipuncture was performed every 12 hours to assess plasma insulin and glucagon. The mean area under the ketone production curve for the nonexercise intervention was 19.19 ± 2.59 mmol/L and 27.49 ± 2.59 mmol/L for the exercise intervention, resulting in a significant 8.30 mmol/L difference between conditions (95% probability interval was 1.94 to 14.82 mmol/L). The mean time to nutritional ketosis was 21.07 ± 2.95 hours with fasting alone, and 17.5 ± 1.69 hours when combined with exercise (posterior probability = 0.89). There was a significant decrease in insulin over time (F(3,133) = 61.75, p < 0.0001). There was also a significant increase in glucagon over time (F(3,133) = 21.10, p < 0.0001). Hunger and stomach discomfort did not differ between conditions. Anger (F(10,394) = 2.74, p = 0.0028), depression (F(10,394) = 2.91, p = 0.0016), tension (F(10,394) = 2.29, p = 0.0128), vigor (F(10,394) = 11.65, p < 0.0001), and fatigue (F(10,394) = 10.60, p = 0.0001) increased over the course of the fast, but did not differ between conditions. Completing aerobic exercise at the beginning of a 36-hour fast results in significantly more ketone production. The impact of exercise on ketone production comes at little or no impact on hunger, stomach discomfort and negative moods. A difference in time to achieving nutritional ketosis between conditions may exist, but this was not observed in this study.

No description available.

Gamma Hydroxybutyrate (GHB) was banned from the consumer market by the Food and Drug Administration in 1991. Despite the ban, use of GHB has continued to contribute to thousands of emergency department visits and numerous fatalities in recent years. Efforts to reduce the use of this drug have had limited impact, which may be the result of using traditional prevention strategies that focus exclusively on educating people about of negative consequences of substance use rather than addressing the factors that motivate use. In an effort to identify motivational factors that could be targeted in future prevention efforts, the present study was designed to examine outcome expectancies for GHB that may promote use of this drug. Methodology that has led to successful strategies to reduce alcohol use was applied to identify GHB expectancies and model cognitive processes likely to encourage or discourage GHB use. Individual differences scaling was used to empirically model a two dimensional semantic network of GHB expectancies stored in memory, and preference mapping was used to model likely paths of expectancy activation for male and female GHB users and nonusers. Differences in expectancies between GHB users and nonusers followed patterns previously identified in relation to alcohol expectancies and alcohol use. Conclusions were limited by relatively low numbers of GHB users in the sample, despite the use of a very large number of participants, overall. Despite this limitation these findings lay the groundwork for development and validation of GHB expectancy based prevention strategies.

Insectivorous bats alter relative use of metabolic substrates to match requirements of their activities, including energetically expensive flight. The “fasting while foraging” hypothesis states that the metabolic demands of flight often exceed energy intake while foraging, hence bats may metabolize fat stores (especially early in the night) to power flight with ketones, a byproduct of the normal oxidation of fatty acids. Previous studies in bats have found increases in the plasma ketone ß-hydroxybutyrate following food consumption paired with or without flight. However, no study has explored whether increases in plasma ß-hydroxybutyrate occur following flight without food consumption. We used metabolite analysis to examine changes in plasma ß-hydroxybutyrate as a function of flight duration in 2 groups (fall and spring) of captive big brown bats (Eptesicus fuscus). We fasted bats for 12 hours prior to flight (exercise treatment) or rest (control), and then collected interfemoral vein blood. Exercise activity was quantified as flight time. For the Fall group, we collected three rest samples and one flight sample. Results for the Fall group were variable; interpretation of data patterns for this group may be complicated by changes in metabolism that occur in the fall when bats physiologically prepare for hibernation. To control for seasonal effects, we tested a second group of bats in the spring, collecting two rest and three flight samples. We found a positive correlation between flight duration and levels of plasma ß-hydroxybutyrate in the Spring group, which supports the fasting while foraging hypothesis. / Thesis / Master of Science (MSc) / The “fasting while foraging” hypothesis states that the metabolic demands of flight can exceed energy intake from recently consumed prey items, so insectivorous bats may metabolize fat stores (especially early in the night) to power flight with ketones, a byproduct of the normal oxidation of fatty acids. Previous studies in bats have found increases in the plasma ketone ß-hydroxybutyrate following food consumption, but no study has explored whether increases in plasma ß-hydroxybutyrate occur following flight without food consumption. We collected and analyzed blood to examine changes in plasma ß-hydroxybutyrate following different flight durations in big brown bats. We explored both seasonal and captivity effects. To explore seasonal effects, we sampled blood from bats in the fall and the spring, times that are biologically significant to big brown bats. The spring is when bats move out of torpor, a form of hibernation, into an active state and the fall is when bats are preparing for entering into torpor. To explore captivity effects, we sampled blood from bats recently introduced to or established to captivity. Bats were fasted for 12 hours prior to flight (exercise treatment) or rest (control), and then blood was collected. We characterized exercise using flight time. We found that plasma ß-hydroxybutyrate increased after longer flight durations, which supports the fasting while foraging hypothesis.

The importance of Poly(3-hydroxybutyrate) (PHB) as a biodegradable material is well known. Due to ever increasing environmental awareness, significant efforts have been made to utilize PHB or its derivatives in producing disposable products. However, brittle mechanical properties of PHB hinder the direct application of this material in useful commodity items. In order to achieve toughened PHB, blending with other polymers which possess high relaxation behavior at room temperature seems attractive. Prior to such development, the fundamental characterization of the relaxation behavior of PHB itself is extremely important in order to assess the effect of any attempt to improve the situation in a quantitative manner. Dielectric thermal analysis was used in the study of the relaxation behavior of melt processed PHB. The approach was largely phenomenological, that was, based on the macroscopic theory of dielectric relaxation. The mean relaxation time of melt processed PHB was evaluated while PHB was undergoing crystallization at room temperature. The experimental conditions were kept as close as possible to actual shelf-life conditions. Dynamic temperature sweep experiments revealed multiple relaxation peaks at the glass transition region. Temperature plane curve resolution revealed, in the early stage of crystallization, two dynamically changing peaks whose behaviors, as the extent of crystallization progressed, were quite opposite in terms of the magnitude of the loss property. By analyzing the temperature dependence of loss property and mean relaxation time, it was concluded that the peak located at the lower temperature is related to pure amorphous chain movement, and the peak located at the higher temperature is related to the movement of amorphous chains which are confined in-between crystalline phases, such as lamellae and spherulites. For the evaluation of the mean relaxation time of binary blends or multiple relaxations arising from homopolymers and copolymers, an empirical model has been developed which is grounded in the theory of linear viscoelasticity with the aim of quantitatively assessing the effect of attempts to improve the toughness of PHB. In the course of data reduction and model development, the majority of empirical dielectric relaxation functions has been reviewed including the Havriliak-Negami model and the Kohlrausch-Williams-Watts stretched exponential function. It was found that the center of relaxation time in the Havriliak-Negami model was skewed toward short time scale of relaxation, while mean relaxation time reflected the relaxation behavior of PHB chains on average, including movement of chains which relax with difficulty as the extent of crystallization progresses. / Ph. D.

L’objectif de cette thèse est le développement des matériaux polymères injectables innovants issus de ressources renouvelables et répondant aux exigences techniques automobiles. Pour cela, des mélanges à base de polyoléfines (POs) et du poly(3- hydroxybutyrate-co-hydroxyvalérate) (PHBV) ont été étudiés. Ces mélanges polymères étant non-miscibles, l’optimisation de leurs propriétés par compatibilisation a été réalisée selon différentes approches. Dans un premier temps, la synthèse de polypropylène fonctionnel original avec des taux de greffage relativement élevés et sans perte de masses molaires a permis, par réaction in-situ, la compatibilisation des mélanges PP/PHBV. Dans une deuxième partie, le poly(éthylène-co- alcool vinylique) greffé-poly(3- hydroxybutyrate-co- hydroxyvalérate) a été synthétisé par extrusion réactive, ce copolymère a été utilisé ensuite comme compatibilisant pour les mélanges PE/PHBV. L’ajout de ces compatibilisants a permis d’obtenir des matériaux ayant des propriétés optimisées et une morphologie nettement plus fine que les systèmes non compatibilisés démontrant ainsi leur efficacité / The main objective of this work is the development of innovative materials from renewable resources for the automotive industry. Polymer blends of polyolefins (POs) and poly(3-hydroxybutyrate-co-hydroxyvalerate) (PHBV) were prepared through twin screw extruder process and studied. These polymer blends are non-miscible, then in order to optimize their final properties, compatibilizing agents were synthesized by reactive extrusion. On the one hand, functionalized polypropylene with various polar monomers and without significant molecular weight loss was synthesized with the aim to compatibilize PP/PHBV blends, on the other hand, poly(ethylene-co- vinylalcohol)-graft- poly(3-hydroxybutyrate-co-hydroxyvalerate) was obtained by exchange reactions in the presence of an efficient catalyst and those in order to compatibilize PE/PHBV blends. Efficiency of these compatibilizers was investigated in the last part of this study which is dedicated to POs/PHBV polymer blends compatibilization. Materials with improved properties and finer morphologies than the non- compatibilized systems were obtained thanks to the compatibilizers

Lim klassificeras som ett ämne som kan hålla ihop två ytor så att de motstår separation. Dagens lim kan anpassas efter vilken applikation de ska användas till och kan ha ett stort antal olika egenskaper. De fysikaliska och kemiska egenskaperna av limmet är de viktigaste faktorerna för att bilda en bra limbindning. I stort sett alla syntetiska lim består idag av polymerer, varav de flesta är petroleumbaserade. För att skapa ett mer miljövänligt alternativ undersökte denna studie tillämpningen av poly(3-hydroxibutyrat- co-3-hydroxivalerat), PHBV med 36 eller 56 vikt% HV, som huvudkomponent i ett lim. Huvudfokus ligger på hur väl PHBV är lämpligt för användning som lim och hur olika tillsatser kan förbättra dess egenskaperna. Flera olika limblandningar innehållande PHBV, mjukgörare (sebacinsyra, dimetylsebacat, etylbutanoat eller tributylcitrat) och förtjockningsmedel (Abalyn eller Foralyn) skapades och undersöktes. Ett single lap skjuvtest utfördes med kopieringspapper, filterpapper och träpinnar som vidhäftningsmaterialet, medan ett avskalningstest undersökte användningen av kopieringspappersetiketter och plastetiketter på en glasflaska samt frukt.  Båda testen visar att kopieringspapper har de mest lovande egenskaperna som en adherent för användningen av ett PHBV-baserat lim, både för PHBV innehållande 36 vikts% och 56 vikts% HV. Denna slutsats kunde dras då kopieringspapperet påvisade den starkaste bindningen med limmet. Ren PHBV uppvisade lovande häftstyrka och vidhäftning som ett smältlim. Tillsatsen av sebacinsyra tillsammans med Abalyn eller dimetylsebacat med Foralyn ökade limmets häftstyrka ytterligare. Vi fann också att lim som skapats med PHBV med 36 vikt% HV ger bättre hållfasthetsegenskaper. Framtida arbete innefattar mer exakta mätmetoder för att bestämma egenskaperna hos limblandningarna. / An adhesive is classified as a substance that holds two surfaces together and resists separation. Today’s adhesives can be modified according to various application demands, obtaining a large variety of properties. The most important factors of forming a good adhesive bond are the physical and chemical properties. Essentially all synthetic adhesives consist of polymers, most of them being petroleum-based. To obtain a more environmentally friendly option, this study investigated the use of poly(3-hydroxybutyrate-co-3-hydroxyvalerate), PHBV with 36 or 56 wt% HV, as the main component in an adhesive. The main focus was to investigate on how well PHBV is suited for use as an adhesive and how different additives can improve the adhesive properties. Several different adhesive formulations containing PHBV, plasticizers (sebacic acid, dimethyl sebacate, ethyl butyrate, or tributyl citrate) and tackifiers (Abalyn or Foralyn) were created and investigated using various tests, such as single lap shear test, peel test, tackiness determination, optical analysis, and application testing. Single lap shear tests were performed using printing paper, filter paper, and wooden sticks as adherents, while peel tests explored the use of printing paper labels and plastic labels on a glass bottle and on fruit. It was determined that two PHBV adhesives, containing 36 wt% and 56 wt% of HV, performed best using printing paper as adherent. This conclusion could be drawn based on the good interaction between the adherent and the adhesive, thereby creating a strong bond. Pure PHBV with 36 or 56 wt% showed promising strength and tackiness properties as a hot-melt adhesive. The addition of sebacic acid together with Abalyn or dimethyl sebacate with Foralyn further increased the adhesive’s strength. It was also found that adhesive formulations created using a PHBV with a lower amount of HV (around 36 wt% of HV) yields better strength properties when used as an adhesive for paper labels. Future work involves more precise measurement methods to determine the properties of the adhesive formulations.

La période de transition, c'est-à-dire de 3 semaines avant à 3 semaines après la parturition, est une période critique pour les vaches laitières puisqu'elles font face à divers changements métaboliques et immunologiques. Pendant cette période, les vaches sont en état de balance énergétique négative causée par l'augmentation de la demande en nutriments pour la production laitière. Pour répondre à cette demande, les vaches doivent mobiliser leurs réserves corporelles ce qui peut entraîner d'importants problèmes de santé. Ce projet avait pour but d'évaluer si la traite incomplète ou la tétée pendant les 5 premiers jours de lactation peut diminuer les problèmes de santé suite à la parturition sans affecter la production laitière subséquente. Quarante-sept vaches Holstein multipares ont été assignées à l'un des 3 traitements suivants. Les vaches du traitement Témoin ont été complètement traites [i.e. traitées] 2x par jour; celles du traitement Incomplet ont été partiellement traites [i.e. traitées] (environ 1/3 du lait a été récolté) 2x par jour jusqu'au jour 5 et celles du traitement Tétée ont été laissées avec le veau qui pouvait téter ad libitum jusqu'au jour 5 en plus d'être traites complètement 1x par jour du jour 3 au jour 5.La production laitière, la consommation alimentaire, certains métabolites sanguins et quelques fonctions immunitaires ont été mesurés sur chacune des vaches. Les traitements n'ont pas affecté la production laitière subséquente des vaches et aucune différence n'a été observée entre les traitements pour la consommation alimentaire. Les vaches des traitements Partiels (Incomplet + Tétée) ont montré des concentrations sanguines 16% plus élevées en glucose, 21% plus faibles en acides gras non estérifiés et 44% plus faibles en bêtahydroxybutyrate. Ces différences de concentrations ont persisté jusqu'au jour 5 pour les acides gras non estérifiés et jusqu'au jour 21 pour le glucose et les bêta-hydroxybutyrate. Bref, les traitements Partiels ont permis d'améliorer la glycémie et de diminuer les concentrations en métabolites sanguins néfastes. Par contre, les fonctions immunitaires évaluées n'ont pas permis de mettre en évidence que la diminution de la récolte en lait en début lactation améliore le statut immunitaire des vaches laitières. Néanmoins, ils ont montré une différence significative entre le jour 2 et le jour 61 pour la prolifération des lymphocytes et la production d'interleukine-4. De plus, une corrélation négative a été observée entre la teneur en acides gras non estérifiés du sérum et la prolifération des lymphocytes. En conclusion, la diminution de la récolte en lait pendant les 5 premiers jours de lactation permet de réduire les désordres métaboliques sans avoir de répercussion négative sur la production laitière subséquente des vaches.