Development of Single and Multimodality Imaging Probes for PET, SPECT and Fluorescence Imaging

This dissertation is in an integrated format discussing three major projects centered around probe development. In the first project, novel metal-chelated and fluorinated GLP-1 derivatives were prepared all containing D-Ala-8, a modification known to improve resistance towards degradation by dipeptidyl-peptidase IV. The effect of increased distance between DOTA and the peptide chain was investigated using a spacer, in order to reduce steric effects imposed by DOTA. Placement of linker and DOTA moieties were varied within the GLP-1 sequence to test for optimal metal-complex location. Binding affinity of peptide derivatives was determined in vitro with CHO/GLP-1R cell line and shown to be in the nM range. In vivo imaging was carried out using C57BL/6 mice. Modifications made to the peptide backbone, based on charge distribution, were shown to improve pharmacokinetics. Our results suggest developed GLP-1 tracers to be potential candidates for the non-invasive imaging of pancreatic islets in vivo. In the second project, Gallium-chelated protoporphyrin IX (PPIX) derivatives containing the tripeptide RGD αvβ3-targeting moiety were prepared and evaluated. Reaction conditions for both naturally occurring 69/71Ga-labeling as well as 68Ga-radiolabeling were optimized using a microwave reactor. Optical properties were evaluated in order to study the effects of ligand conjugation and gallium chelation on absorption/emission properties of PPIX. Quantum yields pre- and post gallium chelation were comparable, indicating that the presence of gallium does not quench the inherent fluorescence of PPIX. The targeted compound was preferentially taken up by αvβ3 integrin-expressing cancer cells versus the non-targeted form, as assessed by fluorescence microscopy. Our results suggest that gallium-PPIX conjugates could be used as dual modality positron emission tomography/fluorescence microscopy probes and can assist in bridging imaging agent discovery from in vitro microscopy through to in vivo imaging. In the third and final project, a novel high-throughput cell-based technique was developed for screening one-bead-one-compound (OBOC) libraries. In order to validate this technique, a small library consisting of heptameric peptides, and the αvβ3 integrins targeting RGD sequence, was synthesized on Tentagel beads via a photo-labile linker. Compounds were screened against the αvβ3-expressing MD 435 cell line. After fluorescent-based sorting, peptides were photolytically cleaved off resin and analyzed using MALDI-TOF/TOF. Deconvolution of all peptide sequences was carried out successfully indicating this screening process to be a facile and efficient technique for discovery of novel targeting entities

Deep Learning in Energy Modeling: Application in Smart Buildings With Distributed Energy Generation

Buildings are responsible for 33% of final energy consumption, and 40% of direct and indirect CO2 emissions globally. While energy consumption is steadily rising globally, managing building energy utilization by on-site renewable energy generation can help responding to this demand. This paper proposes a deep learning method based on a discrete wavelet transformation and long short-term memory method (DWT-LSTM) and a scheduling framework for the integrated modelling and management of energy demand and supply for buildings. This method analyzes several factors including electricity price, uncertainty in climatic factors, availability of renewable energy sources (wind and solar), energy consumption patterns in buildings, and the non-linear relationships between these parameters on hourly, daily, weekly and monthly intervals. The method enables monitoring and controlling renewable energy generation, the share of energy imports from the grid, employment of saving strategy based on the user priority list, and energy storage management to minimize the reliance on the grid and electricity cost, especially during the peak hours. The results demonstrate that the proposed method can forecast building energy demand and energy supply with a high level of accuracy, showing a 3.63-8.57% error range in hourly data prediction for one month ahead. The combination of the deep learning forecasting, energy storage, and scheduling algorithm enables reducing annual energy import from the grid by 84%, which offers electricity cost savings by 87%. Finally, two smart active buildings configurations are financially analyzed for the next thirty years. Based on the results, the proposed smart building with solar Photo-Voltaic (PV), wind turbine, inverter, and 40.5 kWh energy storage has a financial breakeven point after 9 years with wind turbine and 8 years without it. This implies that implementing wind turbines in the proposed building is not financially beneficial.Peer reviewe

Coordination chemistry of amide-functionalised tetraazamacrocycles: structural, relaxometric and cytotoxicity studies

Three different tetraazamacrocyclic ligands containing four amide substituents that feature groups (namely allyl, styryl and propargyl groups) suitable for polymerisation have been synthesised. Gadolinium(III) complexes of these three ligands have been prepared as potential monomers for the synthesis of polymeric MRI contrast agents. To assess the potential of these monomers as MRI contrast agents, their relaxation enhancement properties and cytotoxicity have been determined. A europium(III) complex of one of these ligands (with propargyl substituents) is also presented together with its PARACEST properties. In addition, to gain further insight into the coordination chemistry of the tetra-propargyl substituted ligand, the corresponding zinc(II) and cadmium(II) complexes have been prepared. The X-ray crystal structures of the tetra-propargyl ligand and its corresponding gadolinium(III), zinc(II) and cadmium(II) complexes are also presented

Recent approaches in designing bioadhesive materials inspired by mussel adhesive protein

Marine mussels secret protein-based adhesives, which enable them to anchor to various surfaces in a saline, intertidal zone. Mussel foot proteins (Mfps) contain a large abundance of a unique, catecholic amino acid, Dopa, in their protein sequences. Catechol offers robust and durable adhe-sion to various substrate surfaces and contributes to the curing of the adhesive plaques. In this article, we review the unique features and the key functionalities of Mfps, catechol chemistry, and strategies for preparing catechol-functionalized poly- mers. Specifically, we reviewed recent findings on the contributions of various features of Mfps on interfacial binding, which include coacervate formation, surface drying properties, control of the oxidation state of catechol, among other features. We also summarized recent developments in designing advanced biomimetic materials including coacervate-forming adhesives, mechanically improved nano- and micro-composite adhesive hydrogels, as well as smart and self-healing materials. Finally, we review the applications of catechol-functionalized materials for the use as biomedical adhesives, therapeutic applications, and antifouling coatings

EFL Writing Styles across Personality Traits and Gender: A Case for Iranian Academic Context

The ways individuals use words can reflect basic psychological processes, including clues to their thoughts, feelings, perceptions, and personality. This paper seeks to determine whether there is a relationship between Iranian EFL learners' writing styles and their personality and gender. It focuses on gender and two key dimensions of personality (Neuroticism and Extroversion), which were assessed using Eysenck Personality Questionnaire (revised version). The concept of formality/contextuality was suggested as the most important dimension of variation between linguistic expressions. An empirical measure of formality, the F-score, was suggested, based on the frequencies of different word classes. Nouns, adjectives, prepositions, and articles are more frequent in formal styles; pronouns, adverbs, verbs and interjections are more frequent in contextual styles. The frequency of positive and negative emotional words was calculated by the program Linguistic Inquiry and Word Count. The result shows no significant relationship between these variables. The reason is supposed to be other nonlinguistic determinants of formality (e.g. situation and educational level) which may have a stronger effect on EFL writing styles

EFL Writing Styles across Personality Traits and Gender: A Case for Iranian Academic Context

The ways individuals use words can reflect basic psychological processes, including clues to their thoughts, feelings, perceptions, and personality. This paper seeks to determine whether there is a relationship between Iranian EFL learners' writing styles and their personality and gender.  It focuses on gender and two key dimensions of personality (Neuroticism and Extroversion), which were assessed using Eysenck Personality Questionnaire (revised version). The concept of formality/contextuality was suggested as the most important dimension of variation between linguistic expressions. An empirical measure of formality, the F-score, was suggested, based on the frequencies of different word classes. Nouns, adjectives, prepositions, and articles are more frequent in formal styles; pronouns, adverbs, verbs and interjections are more frequent in contextual styles. The frequency of positive and negative emotional words was calculated by the program Linguistic Inquiry and Word Count. The result shows no significant relationship between these variables. The reason is supposed to be other non-linguistic determinants of formality (e.g. situation and educational level) which may have a stronger effect on EFL writing styles

Fracture Resistance of Simulated Immature Teeth Obturated with Gutta-Percha or Resilon and Reinforced by Composite or Post.

The purpose of this ex- vivo study was to evaluate the fracture resistance of simulated immature teeth, obturated with Gutta-percha or Resilon and reinforced by either composite resin or fiber post.Eighty-four human maxillary incisors were divided into seven groups (n=12). Teeth in all groups were prepared until Peeso #5 (1.5mm) could be passed through the apex. Root ends received 4mm of MTA plug as an apical barrier. Groups received the followings: 1.Gutta-percha, 2.Resilon, 3.Gutta-percha + composite resin, 4.Resilon + composite resin, 5.Gutta-percha + fiber post, 6.Resilon + fiber post and 7.No obturation (control group). Access openings were filled with composite resin. Specimens were then subjected to oblique load using Instron Testing Machine. The mean peak load at fracture was recorded and analyzed using ANOVA.Experimental groups had a significantly more fracture resistance than the control group (P< 0.05). No significant difference was seen between experimental groups. Teeth reinforced by fiber post showed favorable fracture resistance.Treatment plans used in this study increase the fracture resistance of immature teeth. Use of fiber posts in immature teeth, may be the most favorable clinically applicable technique