Type 2 diabetes is a worldwide and costly disease that requires complex cellular metabolic breakdown for its development. The onset of this disease is indicated by an abnormal elevated blood glucose level (hyperglycemia) and coexistence with hypertension. Apple and blueberry are the two popular fruits in the U.S. that are high in bioactive phenolic compounds. The objectives of this thesis were to investigate the synergistic health benefits of apple cider and blueberry juice for potential management of early stages of type 2 diabetes using in vitro enzyme assay models and enhance their synergistic effects through fermentation using probiotic strains of lactic acid bacteria. Apple cider and whole blueberry juice were combined at 5 different ratios. Synergistic interaction of the phenolic bioactives between the two juice sources was observed in all assays. For maintenance of high α-glucosidase, α-amylase and ACE inhibition activities, a proportion of 80% apple cider and 20% whole blueberry juice was selected as the optimum combination reflecting maximum health benefits to potentially manage hyperglycemia and hypertension associated with type 2 diabetes. The 80/20 apple cider and blueberry juice combination was fermented at 24 and 48 h using Lactobacillus helveticus R0052 and Bifidobacterium longum isolate. High inhibition of α-glucosidase, α-amylase and ACE enzymes was observed in apple cider/blueberry juice combination. Strong antimicrobial activity against H. pylori was exerted by L. helveticus- and B. longum-fermented sample at 48 h. A possible mode of action through the synergy between lactic acid and proline oxidation pathway was suggested.

Stamen from Paeonia ostii 'Fengdan Bai' and Paeonia rockii is rich in phenolic compounds and popularly used as tea materials with various pharmaceutical functions. In order to investigate whether stamen from other tree peony cultivars could be used as a natural antioxidant, the quality of stamen from thirty-five cultivars collected from the same garden was evaluated based on their phenolic composition and content by high-performance liquid chromatography analysis and in vitro antioxidant properties coupled with comprehensive chemometrics analysis. The results revealed that phenolic contents and antioxidant capacities of tree peony stamen were unique and cultivar dependent. Stamen from 'Zi Erqiao' exhibited the highest total phenolic and flavonol content, and strongest antioxidant activities, while that of 'Fengdan Bai' and P. rockii were at below-average levels among test samples. Further, thirty-seven cultivars of tree peony were divided into three major groups with a significant difference in total metabolites content and antioxidant properties, which were mainly contributed by six phytochemical compounds. Among these, naringin and benzoylpaeoniflorin were found to be critical chemical markers for the identification of tree peony stamen with high quality by chemometric analysis. Moreover, correlation analysis suggested that stamen from the earlier flowering cultivars with the hidden pistil, double petal, shorter thrum, more carpel and volume were possibly of higher quality. Together, cultivars with stamen enriched in phenolics and antioxidants properties, and their relevant critical phenotypic and phytochemical traits were screened out. This study would benefit the rapid identification of tree peony stamen with high quality and provide a valuable reference for its development and utilization as functional foods and pharmaceutical resources.

Thermal protection systems, which are commonly used to protect spacecraft during atmospheric entry, have traditionally been made of materials which are traditionally high in manufacturing costs for both the materials needed and the manufacturing complexity, such as carbon-carbon composites and aerogels. [1] In addition to their manufacturing costs, these materials are also limited in their strength, such as PICA, in a way that necessitate the use of tiles as opposed to single structures because they are not capable of supporting larger structures. [2] The limitations of polymer reinforced composites have limited their entry into these applications, except for pyrolyzed composite materials, such as carbon-carbon and ceramic composites. These materials have been successfully demonstrated their utility in extreme environments, such as spacecraft heat shields, but their high costs and the difficulty to manufacture them have limited their use to similarly high performance applications where the costs are justifiable. Previous work by others with “fuzzy fiber” composites have shown that aligned carbon nanotubes (CNTs) grown on fibers can improve their thermal conductivity and wettability. To this end vertically aligned CNTs were studied for their potential use, but found to be difficult to process with current conventional techniques. A composite material comprised of basalt, a relatively new reinforcing fiber, and phenolic, which has been used in high-temperature applications with great success was made to attempt to create a new material for these applications. To further improve upon the favorable properties of the resulting composite, the composite was pyrolyzed to produce a basalt-carbon composite with a higher thermal stability than its pristine state. While testing the effects of pyrolysis on the thermal stability, a novel iv technique was also developed to promote in-situ carbon nanotube growth of the resulting basaltcarbon composite without using a monolithic piece of cured phenolic resin in place of the standard aromatic hydrocarbon-catalyst precursor. [3, 4] The in-situ growth of carbon nanotubes (CNTs) was explored as their thermal stability [5] and effectiveness in improving performance has been previously demonstrated when used as a resin additive [6]. The specimens were examined with SEM, EDS, and TGA to determine the effects of both pyrolysis and CNT growth during pyrolysis of the basalt phenolic composites. These tests would confirm the presence of CNTs/CNFs directly grown in the composite by pyrolysis, and confirm their composition by EDS and Raman spectroscopy. EDS would additionally confirm that the surface of the basalt fibers possess a composition suitable for CNT growth, similar to the parameters of CVD processing. Additional testing would also show that the growth behavior of the CNTs/CNFs is dependent on temperature as opposed to composition, indicating that there is a threshold temperature necessary to facilitate the availability of catalysts from within the basalt fibers. The thermal stability shown by TGA indicates that the process of pyrolysis leaves the newly formed composite with a high degree of thermal stability, making the new materials potentially usable in applications such as turbines, in addition to large-scale thermal protection systems.

Работа состоит из введения, основной части (обзор литературы, материала и методы, результаты и обсуждения), заключения и списка литературы. Объектом исследования были каллусные культуры солодки, а также корневище. Цель работы - подобрать условия культивирования, определить содержание суммы фенолов и флавоноидов и антиоксидантную активность каллусной культуры солодки, в сравнении с интактным корневищем. Были получены асептические клеточные линии для двух генотипов солодки. Проведен подбор оптимальных для наращивания биомассы соотношений фитогормонов - наибольшая доля выживших каллусов получена при сочетании фитогормонов: 0,2 мг/л БАП + 20 мг/л НУК, 1 БАП 2 НУК, 1 БАП 20 НУК. Был проведен анализ содержания суммы фенолов и флавоноидов, а также антиоксидантной активности в этанольных экстрактах каллусов и корневища. Показано, что клеточные культуры имеют перспективное значение в качестве получения фенолов и антиоксидантов. Выпускная квалификационная работа магистра – 51 стр., 13 рис., 52 литературных источников, из которых русскоязычных 37, англоязычных 15. / The work consists of an introduction, the main part (review of literature, material and methods, results and discussions), conclusion and list of references. The object of the study was the licorice callus culture, as well as the rhizome. The purpose of the work is to select cultivation conditions, to determine the content of the sum of phenols and flavonoids and antioxidant activity of licorice callus culture, in comparison with the intact rhizome. Aseptic cell lines were obtained for two licorice genotypes. The ratios of phytohormones optimal for biomass growth were selected - the largest share of surviving calli was obtained with a combination of phytohormones: 0.2 mg / L 6-BA + 20 mg / L NАА, 1 6-BA 2 NАА, 1 6-BA 20 NАА. An analysis was carried out of the content of the sum of phenols and flavonoids, as well as the antioxidant activity in ethanol extracts of callus and rhizome. Cell cultures have been shown to have promising value as phenols and antioxidants. The final qualifying work of the master is 51 pages, 13 figures, 52 literary sources, of which 37 are Russian-speaking and 15 are English-speaking.

Strengthening potential of single-walled carbon nanotubes (SWCNTs) in a phenolic resin composite was evaluated by characterization of purified and phenyl sulfonated SWCNTs, investigation of the load transfer capability of the purified SWCNTs, and characterization of the composites. Purified and phenyl sulfonated SWCNTs, as well as their composites, were examined by Raman spectroscopy, thermogravimetric analysis, scanning electron microscopy equipped with energy dispersive spectroscopy, transmission electron microscopy, X-ray photoelectron spectroscopy and ultra violet-visible spectrometry. Fabrication of the SWCNT/phenolic resin composite was performed by first dispersing the SWCNTs in ethylene glycol and then homogenizing the mixture with phenolic resin. The ethylene glycol was then evaporated from the mixture and the SWCNT/phenolic resin composite was cured at 200°C for 1 hour. The dispersion of SWCNTs in the phenolic resin was reduced with higher SWCNT concentrations. Load was transferred from the phenolic resin to the purified SWCNTs. This demonstrated the potential to strengthen phenolic resin composite with SWCNT reinforcement. The load transfer efficiency in total tension (0.8%) decreased with an increase in SWCNT concentration, while in total compression (-0.8%), the load transfer efficiency remained constant. At very low strain (± 0.2%), the load transfer efficiency remained constant regardless of SWCNT concentration in both tension and compression. Characterization of the phenyl sulfonated SWCNTs indicated that calcium was introduced as a contaminant that interfered with functionalization of the SWCNTs. The use of contaminated phenyl sulfonated SWCNTs resulted in macroscopic inhomogeneity within the composite.

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Research was conducted to investigate the effect of phenolic compounds derived from inherently rich antioxidant grape extracts (GE) on α-glucosidase inhibitory activity in vitro and in vivo blood glucose control, oxidative stress, and inflammation associated with obesity-induced type 2 diabetes. Because intestinal α-glucosidase plays a key role in the digestion and absorption of complex carbohydrates, the inhibition of this enzyme is a metabolic target for managing diabetes by improving post-prandial blood glucose control. Initially, red Norton wine grape (Vitis aestivalis) and pomace extracts were evaluated and determined to have notable phenolic content and antioxidant properties. Next, grape skin (GSE) and pomace extract (GPE) were tested and both had in vitro yeast and mammalian α-glucosidase inhibitory activity. The GSE was 32-times more potent at inhibiting yeast α-glucosidase than acarbose, a commercial oral hypoglycemic agent. From HPLC and LC-MS analysis, three phenolics from the GSE (resveratrol, ellagic acid, and catechin) were identified as active inhibitory compounds. The acute administration of GPE (400 mg/kg bw) to mice reduced postprandial blood glucose level by 35% following an oral glucose tolerance test compared to the control. The daily supplementation (250 mg/kg bw) of GSE and GPE for 12-weeks to mice affected fasting blood glucose levels, oxidative stress, and inflammatory biomarkers associated with obesity and type 2 diabetes. At the end of the study, the GSE group gained significantly (P < 0.05) more weight (24.6 g) than the control, high fat, or GPE groups (11.2, 20.2, 19.6 g, respectively). Both GSE and GPE groups had lower fasting blood glucose levels (119.3 and 134.2 mg/dL, respectively) compared to the high fat group (144.6 mg/dL). The 12-week supplementation of GSE was associated with a higher plasma oxygen radical absorbance capacity (ORAC), lower liver lipid peroxidation as measure by TBARS, and lower levels of inflammation as measured by plasma C-reactive protein compared to the high fat group. In conclusion, our collective observations from these studies provide insight into the potential effects of antioxidant rich grape extracts on diabetes-related biomarkers through a dual mechanism of antioxidant protection and specific inhibition of intestinal α-glucosidases. / Ph. D.

Void-free phenolic networks have been prepared by the reaction of phenolic novolac resins with various diepoxides. The stoichiometric ratio can be adjusted to achieve networks with good mechanical properties while maintaining excellent flame retardance. A series of linear, controlled molecular weight, 2,6-dimethylphenol endcapped cresol novolac resins have been synthesized and characterized. The molecular weight control was achieved by adjusting the stoichiometric ratio of cresol to 2,6-dimethylphenol and using an excess of formaldehyde. A dynamic equilibrium reaction was proposed to occur which allowed the targeted molecular weight to be obtained. A 2000 g/mol ortho-cresol novolac resin was crosslinked by a diepoxide oligomer and by an epoxidized phenolic oligomer in defined weight ratios and the structure-property relationships were investigated. The networks comprised of 60 or 70 weight percent cresol novolac exhibited improved fracture toughness, high glass transition temperatures, low water uptake, and good flame retardance. The molecular weights between crosslinks were also determined for these networks. The stress relaxation moduli were measured as a function of temperature near the glass transition temperatures. Crosslink densities as well as the ability to hydrogen bond affect the glassy moduli of these networks. Rheological measurements indicated that cresol novolac/epoxy mixtures have an increased processing window compared to phenolic novolac/epoxy mixtures. Maleimide functionalities were incorporated into cresol novolac oligomers, and these were crosslinked with bisphenol-A epoxy. The processability of oligomers containing thermally labile maleimides were limited to lower temperatures. However, sufficiently high molecular weight oligomers were necessary to obtain good network mechanical properties. Networks prepared from 1250 g/mol cresol novolac containing maleimide functionilities and epoxy exhibited good network properties and could be processed easily. Latent triphenylphosphine catalysts which are inert at processing temperatures (~140°C) but possess significant catalytic activity at cure temperatures 180-220°C were necessary for efficient composite fabrication using phenolic novolac/epoxy matrix resins. Both sequestered catalyst particles and sizings were investigated for this purpose. Phenolic novolac/epoxy mixtures containing sequestered catalysts exhibited significantly longer processing time windows than those containing free catalysts. The resins also showed accelerated reaction rates in the presence of sequestered catalysts at cure temperatures. Trihexylamine salt of a poly(amic acid) was sized onto reinforcing carbon fibers and the composite properties indicated that fast phenolic novolac/epoxy cure could be achieved in its presence. / Ph. D.