cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Utility of Cationic and Anionic Chiral Surfactants in Capillary Electrophoresis (CE) and CE Coupled to Mass Spectrometry (CE-MS)
Creators: name: Wang, Bin
Publisher: name: Georgia State University
Year: 2009

description: The research presented in this thesis involves the application of chiral cationic and anionic surfactants for simultaneous enantioseparation of structurally similar compounds in capillary electrophoresis (CE) and CE coupled to mass spectrometry (CE-MS).  The first chapter briefly introduces the fundamentals of CE and CE-MS, emphasizing the micellar electrokinetic chromatography (MEKC) and MEKC-MS techniques, as well as ionic liquids (ILs) and affinity CE (ACE).

    In chapter 2, a mixture of five racemic profen (PROF) drugs are simultaneously separated with the combined use of 2,3,6-tri-O-methyl-β-cyclodextrin (TM-β-CD) and IL-type surfactant, N-undecenoxycarbonyl-L-leucinol bromide (L-UCLB).  Enantioseparations of these PROFs are optimized using a standard recipe containing 35.00 mM TM-β-CD, 5.00 mM sodium acetate at pH 5.0, and varying the concentration as well as chain length of the IL surfactants.  The batch-to-batch reproducibility of L-UCLB is found to be acceptable in terms of enantiomeric resolution, and migration time.  A competitive inhibition mechanism is proposed to investigate the ternary interactions among TM-β-CD, ILs, and PROFs.  The apparent binding constant of TM-β-CD to L-UCLB is estimated by nonlinear and linear plotting methods.  The binding constants of one representative PROF (e.g., fenoprofen) to TM-β-CD and to L-UCLB are estimated by a secondary plotting approach.  The R- and S-fenoprofen having different binding constant values, resulting in the enantioseparation due to the synergistic effect of TM-β-CD and L-UCLB. 

    The R- and S-configurations of barbiturates display differences in potency and biological activity.  In Chapter 3, a multivariate MEKC-ESI-MS approach for the simultaneous analysis of the racemic mixture of three barbiturates is presented.  The chiral selector employed is the polymeric surfactant polysodium N-undecenoxycarbonyl-L-isoleucinate.  The central composite design is used to optimize the chiral resolution, decrease the total analysis time, and improve the ESI-MS signal-to-noise ratio for these barbiturates.  In preliminary experiments, the ranges of the factors investigated in the multivariate approaches are determined.  Then the multivariate optimizations are conducted to determine the best overall chiral resolution with shortest possible run times for barbiturates.  The limit of detection of ESI-MS is several folds higher compared to the UV detection.  The predicted optimum results are in good agreement with the experimental data.
Structural Factors that Influence the Inhibition of Type II Restriction Enzymes by Minor Groove Binders
Creators: name: Nguyen, Ha
Publisher: name: Georgia State University
Year: 2009

description: The objective of this thesis was to study whether heterocyclic dicationic compounds that are minor groove binders have the ability to inhibit the digestive properties of type II restriction enzymes which bind to the major groove of the DNA. If these compounds do possess the ability to inhibit restriction enzymes, then what factors influence their ability to inhibit the restriction enzymes? The methods used to study the interactions of DNA, compounds, and enzymes are gel electrophoresis, DNA thermal melting, and circular dichroism. The results from this project reveal that the minor grove binding compounds are able to inhibition type II restriction enzymes. The inhibition is heavily influenced by compound structure and the DNA binding sequence of the enzyme.
Heterocyclic Diamidines Induce Sequence Dependent Topological Changes in DNA; A Study Using Gel Electrophoresis
Creators: name: Tevis, Denise
Publisher: name: Georgia State University
Year: 2009

description: Diamidines are a class of compounds that target the minor groove of DNA and have antiparasitic and antimicrobial properties.  Their mechanism of action has not been fully elucidated, but may include changes in DNA topology.  In this study we have investigated such changes using methods of gel electrophoresis including ligation ladders and cyclization assays.  We found that topology changes were sequence dependent.  Compounds typically caused non-anomalously migrating ATATA sequences to migrate as if they were bent, while A5 sequences that normally migrated anomalously became less so in the presence of certain diamidines.  Select compounds induced changes in cyclization efficiency that were also sequence dependent; DB75 significantly abolished cyclization in A5 containing sequences but enhanced it in sequences containing ATATA sites.
A Novel Method for the Quantitative Evaluation of Fibrinogen Coagulation
Creators: name: Liu, Yidan
Publisher: name: Georgia State University
Year: 2009

description: Fibrinogen aggregation is the last step in blood coagulation. Inhibition of fibrinogen aggregation could lead to anticoagulation effects. However, there is no good method for the ready evaluation of fibrinogen coagulation. A commonly used path method is slow and requires an expensive instrument. In this project, we have developed a microplate reader and In evaluating inhibitors of fibrinogen coagulations there is no good method. As an important process in hemostasis, fibrinogen coagulation is often detected by micro-plate reader. In our test of fibrinogen coagulation, we improved the observing and analyzing method by using photograph to see concentration-depended effect of thrombin inhibitors on the coagulation. Three known thrombin inhibitors, AEBSF, APMSF and PMSF, were applied to develop the method for detecting the fibrinogen coagulation. The results showed our method is of accuracy in determination of the amount of fibrin when compared with other types of methods.
Expression and Purification of Engineered Calcium Binding Proteins
Creators: name: Castiblanco, Adriana
Publisher: name: Georgia State University
Year: 2009

description: Previous studies in Dr. Yang?s laboratory have established a grafting, design, and subdomain approach in order to investigate the properties behind Ca2+-binding sites located in Ca2+-binding proteins by employing engineered proteins. These approaches have not only enabled us to isolate Ca2+-binding sites and obtain their Ca2+-binding affinities, but also to investigate conformational changes and cooperativity effects upon Ca2+ binding.

The focus of my thesis pertains to optimizing the expression and purification of engineered proteins with tailored functions. Proteins were expressed in E. coli using different cell strains, vectors, temperatures, and inducer concentrations. After rigorous expression optimization procedures, proteins were further purified using chromatographic and/or refolding techniques. Expression and purification optimization of proteins is essential for further analyses, since the techniques used for these studies require high protein concentrations and purity. Evaluated proteins had yields between 5-70 mg/L and purities of 80-90% as confirmed by SDS-PAGE electrophoresis.
Site Directed Mutagenesis, Expression and Enzymatic Studies of the 60 kDa Human HIV-TAT 1 Interactive Protein, TIP60
Creators: name: Elangwe, Emilia
Publisher: name: Georgia State University
Year: 2009

description: Tip60 is a 60 kDa nuclear protein which exists in three isoforms, belongs to the MYST/HAT family of proteins and was discovered after its interaction with the Human HIV-1 Tat. As a nuclear protein, Tip60 can act as a coactivator or repressor. To understand the HAT action of Tip60, two possible catalytic models exist; the ping-pong and the ternary complex formation models. In correlation with the exploration of HAT catalytic action, mutations of a Cys to Ala and a Glu to Gln on Esa1 (yeast homolog of Tip60 and MYST/HAT prototype), was reported to show wild type-like and decreased acetylating properties, respectively. In this work, Tip60 HAT action was explored. In Tip60, the Cys in the active site is important for acetylation of the H4(1-20) substrate and the Glu showed semi loss in acetylating the H4(1-20) peptide substrate. These data highlight a unique mechanism of Tip60 catalysis.
Synthesis Of Potential Anti-Leishmania Dicationic Diaryldiamidines
Creators: name: Shareef, Abdur-Rafay
Publisher: name: Georgia State University
Year: 2005

description: Dicationic diamidines synthesized in the Boykin group a have shown broad range of activity against a wide variety of microbial pathogens such as Cryptosporidium parvum, Leishmania donovani, Plasmodium falciparum, Trypanosoma burcei, and Trichomonas vaginalis. Thiophene based dicationic diamidines have been especially impressive versus Trichomoniasis, and several
species of the leishmania parasite. The best compound in vitro against leishmania was 2,5-bis-(4-amidophenyl)thiophene [DB 351]. In an attempt to improve upon antileishmanial activity, several analogs of DB 351 have been synthesized. Previously the central heterocyclic ring has been
changed (furan, pyrrole, etc.), and the phenyl has been substituted with a pyridine ring, however, in the thiophene series, the 3 and 4 position of the central thiophene ring has remained unmodified. By modifying the 3 and 4 position of the thiophene ring, and taking advantage of the substituent effect, the pharmacodynamic and distribution properties of DB 351 will altered; hopefully leading to more potent antileishmanial compounds.
Understanding molecular origin of efficient and stable organic photoconversion devices
Creators: name: Labanti, Chiara
Publisher: name: Imperial College London
Year: 2023

description: Organic semiconductors (OSCs) are sparking great interest for their potential to substitute inorganic-based technologies (e.g., silicon) in optoelectronic device applications. In recent years, both organic photovoltaics (OPVs) and organic photodetectors (OPDs) have reported dramatic and steady progress in performances, with additional attractive characteristics of lightweight, colour-tunability/transparency, mechanical exibility, and low-cost fabrication. However, for organic optoelectronics to be ready for the market as a reliable alternative to silicon counterparts, further performance and lifetime increase is required. This involves, for example, improving photodetection speed and reducing dark currents in OPDs, and suppressing OPV photodegradation mechanisms. In this thesis, both design of OSC molecular structure and engineering of device active layer are utilised as powerful tools to improve e ciency of photon-to-electron conversion processes in OPVs and OPDs and to extend operational lifetimes, in both solution-processed and vacuum-evaporated devices. Firstly, the e ect of di erent modi cations in OSC chemical structures is analysed, including heteroatom substitution and end-group engineering in nonfullerene acceptors, and geometry control in small-molecule donors. By detailed investigation of molecular physics combining energetic (by air photoemission spectroscopy) and structural (by Raman spectroscopy) characterisation, the role of these modi cations on device performance is pinpointed. In particular, backbone rigidity and ne-tuning of charge delocalisation along the molecule are found essential to suppress chemical and morphological degradation during OPV operations, while the adoption of di erent donor conformations (twisted vs. planar) determines trapstate distribution and photodetection speed in OPDs. Secondly, OPD active layer characteristics are engineered by fabrication parameter tuning, taking into account factors like donor:acceptor ratio and thickness. Here, it is found that high content of donor polymer is crucial to suppress dark current and ensure fast photodetection by morphology and energetic optimisation, while thickness increase in evaporated blends can control molecular orientation and packing order, which is particularly promising in fullerene-free OPDs.
SIAA and Neat2 Heme Binding Proteins from Streptococcus Pyogenes
Creators: name: Delgado, Giselle
Publisher: name: Georgia State University
Year: 2009

description: The bacterium Streptococcus pyogenes requires heme, which is taken up via an ABC transporter. An understanding of this pathway may result in new approaches to antibacterial agents. Both SiaA and NEAT2 (NEAr Transporter 2) are proteins involved in heme binding. One of the axial ligands of SiaA, His 229, was purified to study how mutagenesis affects heme binding. UV-visible studies showed a small band at 420 nm with respect to the protein band at 288 nm which probably indicates that heme was lost easily from this mutant. We have also worked to optimize the yield of Shr-NEAT2 by changing different variables. For each of the batches, the yield of holoNEAT2 was calculated by UV-visible spectroscopy. Increasing oxygen during growth did not improve holoNEAT2 yield. On the other hand, lower temperature, decrease in time after induction, and addition of ALA all increased the protein production.
Biochemical Study of Engineered Fluorescent Proteins as Calcium Sensors and the Effect of Calcium and PH in Cell Reproduction and Protein Expression
Creators: name: Delgado, Malcom
Publisher: name: Georgia State University
Year: 2009

description: Calcium plays important roles in both eukaryotic and prokaryotic cells. Its actions help to stabilize cell synthesis, growth and development.
In this thesis, studies have been completed to determine effects of calcium and pH on bacterial cell growth and protein expression using the bacterial cell strain E.coli BL21(DE3). Our studies demonstrated the addition of calcium addition in the media does not affect growth but increases protein expression, while reducing the pH from 7 to 4 through the addition of 10mM EGTA in LB media inhibits both.
Additionally, we report studies on the design, expression, and purification of fluorescent mCherry variants and their differences in their optical properties, including: extinction coefficients , quantum yields and pKa values. Also, we report progress in the crystallization of two GFP calcium sensors: G1 and D1, using 13 and15% PEG 4000 and 3350 respectively in 50mM HEPES buffer (pH 6.8-7.0) in an effort to optimize crystallization.
The Kinetics of Epoxidation of A,B-Unsaturated Esters by Dimethyldioxirane: A Mechanistic Study
Creators: name: Sansone, John
Publisher: name: Georgia State University
Year: 2009

description: The epoxidation of a series of …,?-unsaturated esters by dimethyldioxirane was studied. Second order rate constants were determined under pseudo first order conditions. The epoxide of each ester upon full conversion was found to be the only isolable product. Second order rate constants for the cis-like ethyl tiglate showed a 4 fold increase over that of trans-like angelic methyl ester. The ester substituent was found to have little effect on overall rate constants. A comparison of a relatively strained cyclopentene carboxylate to the cyclohexene carboxylate showed a 2 fold increase in selectivity for the former. Ethyl methacrylate displayed unexpected reactivity toward dioxirane; undergoing reaction faster than more substituted electron rich alkenes. Computer modeling studies using the AM-1 and density functional approaches were carried out to gain insights into the mechanistic aspects of the reaction. The esters in general favored the S-cis conformation or were evenly distributed among S-cis and S-trans except for the ethyl
methacrylate case. The AM-1 approach did not predict the reactivity of open chain esters. The density functional approach predicted the relative reactivity of seven of the nine esters but could not predict the reactivity when the R1 group was substituted. One possible explanation is that the computer model predicts the methyl groups of the dioxirane to be positioned over the R1 group in the lowest energy of all other esters, but steric clash prevents this for angelic methyl ester and ethyl 3,3 dimethyl acrylate.
Heterocyclic Cations as Potential Anticancer Agents: An Approach that Targets G-quadruplex with Different Binding Modes
Creators: name: Musetti, Caterina
Publisher: name: Georgia State University
Year: 2010

description: G-quadruplex structures are found in important regions of the eukaryotic genome, such as telomeres and regulatory sequences of genes, and are likely to play important roles in regulation of biological events. The significant structural differences with duplex DNA make quadruplex DNA a very attractive target for anticancer drug design. The purpose of this study is to explore conformational space in a series of heterocyclic cations to discover novel structural motifs that can selectively bind and stabilize specific G-quadruplex arrangements. A variety of biophysical techniques such as thermal melting experiments, biosensor surface plasmon resonance, circular dichroism, fluorescence displacement assay and mass spectrometry were employed to evaluate the affinity of the compounds and their recognition properties. The screening of the molecules allowed the identification of not only selective G-quadruplex ligands but also potential quadruplex groove binders. These results can be useful for the development of new efficient telomerase inhibitors which are endowed with pharmacological activity.
Study of Cyanine Dye Binding to Amino Acids and Its Analytical Utility
Creators: name: Merid, Yonathan
Publisher: name: Georgia State University
Year: 2010

description: Investigation of the NIR cyanine dye MHI-36 shows binding affinity to charged amino acids. This cyanine dye showed aggregation and dimer formation at higher dye concentration (2.0x10-3 M) induced by lysine. When dye concentration decreased to 1.0x10-4M no strong aggregate formation was viewed. Dye shows strong binding and selectivity properties towards charged amino acids lysine and arginine, compared to neutral leucine. It?s believed the positively charged presence was able to break and disrupt the conjugated ?- ? bonds at lower dye concentration. Computational work showed intramolecular aggregation of the phenyl groups on the dye. These aggregates are believed to create electron rich environment suitable for lysine interaction.
Outlining the Invisible: Experiences and Perspectives Regarding Concussion Recovery, Return-to-Work, and Resource Gaps
Creators: name: Karmali, Shazya
name: Beaton, Marie Denise
name: Babul, Shelina
Publisher: name: Multidisciplinary Digital Publishing Institute
Year: 2022

description: Appropriate supports and accommodations are necessary to ensure full concussion recovery and return-to-work (RTW). This research investigated barriers and facilitators to concussion recovery and RTW, and resource gaps reported by adults with concussion (‘workers’) and workplace and healthcare professionals (‘workplaces’). Semi-structured interviews and focus groups were conducted with workers (n = 31) and workplaces (n = 16) across British Columbia. Data were analyzed using inductive content analysis. Facilitators to workers’ concussion recovery and RTW included treatment, social support, and workplace and lifestyle modifications. To address barriers, both groups recommended: (a) widespread concussion and RTW education and training (b) standardized concussion recovery guidelines; (c) changing attitudes toward concussion; (d) mental health supports; and (e) increasing awareness that every concussion is unique. Findings can inform best practice for concussion recovery and RTW among professionals in workplaces, healthcare, occupational health and safety, and workers’ compensation boards.
Synthesis of Near-Infrared Heptamethine Cyanine Dyes
Creators: name: Gragg, Jamie
Publisher: name: Georgia State University
Year: 2010

description: Carbocyanine dyes are organic compounds containing chains of conjugated methine groups with electron-donating and electron-withdrawing substituents at the terminal heterocycles of the general formula [R1-(CH)n-R2]+X-. The synthetic methodology and optical properties of carbocyanines will be discussed. This thesis consists of two parts: (A) synthesis and optical properties of novel carbocyanine dyes substituted with various amines and the synthesis of unsymmetrical carbocyanine dyes containing monofunctional groups for bioconjugation. (B) synthesis of heptamethine carbocyanine dyes to be used for image-guided surgery. In part A, the synthesis of carbocyanine dyes functionalized with various amines and studies of their optical properties with respect to absorbance, fluorescence, quantum yield and extinction coefficient will be presented. These property studies will aid in designing efficient dyes for future biomedical applications. Part A will also include a one pot synthesis of unsymmetrical carbocyanine dyes functionalized with mono carboxylic acid chains, useful for biomolecule (i.e. proteins, amino acids, etc.) conjugation. Part B will describe the synthesis of novel carbocyanine dyes to be used for cancer image-guided surgery. Cancers are thus far incurable diseases, i.e. there are no drugs currently available to cure cancer; however, by designing a dye to visualize tumor cells will greatly increase the efficiency of cancer removal and hopefully increase the survival rate of cancer patients. The dyes reported in this thesis are superior to commercially available dyes used to visualize and identify various tumors invisible to the naked eye of surgeons with regards to biodistribution and clearance through kidney filtration.
Synthesis of Substituted Pyrimidines and Pyridines as Ligands to the 5-HT7 Receptor
Creators: name: Blake, Ava
Publisher: name: Georgia State University
Year: 2010

description: Of the seven existing classes of serotonin receptors, the 5-HT7 receptors (5-HT7Rs) are the most recently discovered. Abundance of 5-HT7 in the central nervous system is suggestive of the receptor?s role in several physiological and pathophysiological functions. Existing research has afforded a number of compounds exhibiting specific affinity to the receptor. These selective ligands can provide structural information about the receptor and can serve as the foundation for pharmacological profiling . This thesis describes the synthesis of substituted pyrimidines and pyridines for affinity to the 5-HT7 receptor. Organometallic species are the cornerstone for sev-eral of the synthetic pathways.
An Analysis of Prominent Water Models by Molecular Dynamics Simulations
Creators: name: Johnson, Quentin
Publisher: name: Georgia State University
Year: 2010

description: Water is the most common solvent for most biological reactions, therefore it is vital that we fully understand water and all its properties. The complex hydrogen bonding network that water forms can influence protein-protein and protein-substrate interactions and can slow protein conformational shifts. Here, I examine an important property of water known as energetic roughness. The network of interactions between individual water molecules affect the energy landscape of proteins by altering the underlying energetic roughness. I have attributed this roughness to the making and breaking of hydrogen bonds as the network of hydrogen bonds constantly adopts new conformations. Through a novel computational approach I have analyzed five prominent water models and have determined their inherent roughness to be between 0.43 and 0.62 kcal/mol.
Determining Topological Effects of Heterocyclic Diamidines with AT Rich DNA: A Study Using Gel Electrophoresis, Mass Spectrometry, and the Polymerase Chain Reaction
Creators: name: Hunt, Rebecca
Publisher: name: Georgia State University
Year: 2010

description: Diamidines are compounds with antiparasitic properties that target the minor groove of DNA. The mechanism of action of these compounds is unknown, but topological changes to DNA structure are a possibility. In this study, we have developed a polyacrylamide gel based screening method to determine topological effects of diamidines on four target sequences: AAAAA, TTTAA, AAATT, and ATATA. The changes caused are sequence dependent, but generally the effect on AAAAA and AAATT is the same while the effect on TTTAA and ATATA is the same. A few compounds show interesting sequence dependent topological effects in the polyacrylamide screening method that could be caused by the compound forming a dimer. Mass spectrometry is used to determine the stoichiometry of DNA-compound complexes. Once compounds show topological effects in the screening method, a bent fragment of kinetoplast DNA is isolated to determine if the same effects occur with DNA from a parasite.
Garment ageing in a Laundry care process under household-like conditions
Creators: name: Heller, Claudia
name: Bannick, Claus Gerhard
name: Altmann, Korinna
name: Braun, Ulrike
name: Kerndorff, Alexander
Publisher: name: My University
Year: 2023
Subjects: Mikroplastikpartikel
Waschverfahren

description: This study reflects typical consumer textile washing behaviour while taking into account existing standards in the household appliance and garment industries. Two garments were washed repeatedly with artificial dirt and detergent 30 times. The collected washing water was separated using fractional filtration. Textile physical tests were used to follow property changes of the garments, the microplastic release is determined using thermoextraction/desorbtionâ€Ìgas chromatography/mass spectrometry and the total organic carbon was measured as a sum parameter for the organic bonded carbon. This article shows the importance of a reality-based approach when investigating microplastics of textile origin in the laundry care process. Deposits of detergent and dirt on the textiles were detected. The total mass of sieve residues was much higher than the release of synthetic polymers. The cotton content of the garments causes a much higher fibre release than synthetic fibres. Both will lead to false results by purely gravimetric analysis because nonpolymer fibres will be included microplastic mass. The results cannot be generalised only by the main polymer type, knowledge of the textile construction must be included for final evaluation. © 2023 Wiley-VCH GmbH.
Synthesis of Selective 5-HT6 and 5-HT7 Receptor Antagonists
Creators: name: Raux, Elizabeth
Publisher: name: Georgia State University
Year: 2010

description: The development of novel selective 5-HT6 and 5-HT7 receptor antagonists is an ever-growing area of interest among medicinal chemists. The potential of developing a therapeutic agent useful as an antipsychotic or antidepressant, as well as the possibility to develop a drug for Alzheimer?s disease and obesity has led to an increase in synthesis of possible lead compounds. The synthesis of unfused biheteroaryl derivatives is described within. The derivatives have been evaluated for binding affinity at 5-HT2A, 5-HT6 and 5-HT7 receptors. The most potent 5-HT6 receptor antagonists include a benzene ring, a hydrophobic group and a protonated nitrogen atom. The most potent and selective compound synthesized is 1-[3-butyl-5-(thienyl)phenyl]-4-methylpiperazine. The binding site of the 5-HT7 receptor is similar to that of the 5-HT6 receptor and the most selective and potent 5-HT7 receptor antagonist also contains a potonated nitrogen atom and a hydrophobic group. The difference in selectivity between the 5-HT6 and 5-HT7 receptor antagonists is the aromatic ring. The most potent 5-HT7 receptor antagonist synthesized contains a pyridine ring instead of benzene, as in the 5-HT6 receptor antagonist. The most potent and selective 5-HT7 receptor antagonist is 1-[4-(3-furyl)-6-methylpyridin-2-yl]-4-methylpiperazine. The need to increase selectivity for both 5-HT6 and 5-HT7 receptors has led to the synthesis of flexible-chain linked derivatives and the results are described within.
Purification and Structural Characterization of a Novel Class of Protein- Based Magnetic Resonance Imaging Contrast Agents
Creators: name: Hubbard, Kendra
Publisher: name: Georgia State University
Year: 2010

description: More than one-third of all Magnetic Resonance Imaging (MRI) scans employ image-enhancing contrast agents to increase the differential signal intensity between diseased and normal tissue. Because current clinical contrast agents exhibit low relaxivity (mM-1 s-1), low dose efficiency, and rapid secretion, we have designed a group of protein-based MRI contrast agents with multiple gadolinium binding sites. In this study, the developed purification method for Class ProCA-3 agents allows for a quick and cost-effective way to abstract up to 109 mg of pure, soluble protein from a 1L E. Coli cell pellet devoid of DNA or RNA ?contamination? for extensive animal studies. Circular dichroism far-UV spectra ensure the metal stability of the agents, revealing maintenance of their native …-helical structure in the presence and absence of metal ions. Furthermore, substantial evidence supports the high dose efficiency of these agents, exhibiting up to five folds higher relaxivity than their analogous commercial competitors.
Development of a Novel DNA Microchip for Pathogen Detection
Creators: name: Maw, Khin
Publisher: name: Georgia State University
Year: 2010

description: Although DNA microarray can detect multiple DNA samples simultaneously, current detection techniques involve PCR and other traditional procedures. In this study, a sensitive, specific and rapid detection method, which eliminates PCR and other lengthy processes, for pathogenic DNA is presented. This technology is based on the hybridization of target DNA to the immobilized probe, extension of probe DNAs using the target-DNA as a template and signal generation by streptavidin-horseradish peroxidase and substrate. This method is highly specific and sensitive, allowing single-nucleotide-base mismatches discrimination and the detection at femtomole level. The experiments are designed to achieve short hybridization time. Therefore, satisfactory signal can be detected within minutes, allowing the rapid detection of multiple pathogenic DNA. Most importantly, the E. coli genomic DNA can be detected using this technology. In conclusion, this detection method is useful for applications including on-site pathogenic disease detection, crime scene investigation, and pathogen inspection in the environment.
Photocleavable Linker for Protein Affinity Labeling to Identify the Binding Target of KCN-1
Creators: name: Tran, Hang
Publisher: name: Georgia State University
Year: 2010

description: KCN-1 is known to reduce tumor growth 6-fold in mice implanted with LN229 glioma cells.  Although this inhibitor is effective, the mechanism of action for KCN-1 is not well understood.  Based on preliminary studies, KCN-1 reduces tumor growth by disrupting the HIF 1 (hypoxia-induced factor-1) pathway.  The binding target of KCN-1 needs to be investigated in order to develop KCN-1 or its analogs for therapeutic applications.  In this research, a molecule was designed and synthesized for the identification of the binding target of KCN-1.  Specifically, this molecule contains the inhibitor (KCN-1), a photocleavable linker, beads, and the affinity label (L DOPA).  When UV light shines on the linker, the trans-alkene isomerizes to cis-alkene and undergoes intramolecular ring-closing reaction, which helps cleave the immobilized bead from the linker.  The immobilized bead is used to separate the binding fragment attached to the photocleavable linker from the solution after enzyme digestion.  The affinity label (L-DOPA) reacts with a nucleophile from the binding target and creates a covalent bond.  If the design is successful, this method is able to analyze the mass of the peptide sequence and determine the binding target of KCN-1.
Theoretical Modeling of Oligopeptides through Capillary Electrophoresis and Tarnsport Studies
Creators: name: Twahir, Umar
Publisher: name: Georgia State University
Year: 2011

description: Within this study, the focus will be on oligoglycines. Numerous studies pertaining to the mobility and conformations of oligoglycines have been completed, as this is a driving force for the study. The oligopeptide is modeled using a ?coarse-grained? model created in the Allison lab at Georgia State University [Xin,Y.,et. al, J. Phys. Chem. B 2006, 110, 1038-1045], which will be briefly explained within this paper. Oligoglycines will be studied in a few different systems, as the overall charge on the peptide and system will affect its mobility. The conclusion drawn is that the peptide adopts three different conformations based on the temperature of the system and length of the peptide; random conformation at high temperatures, and compact conformations at low temperature. Oligoglycines of length three to five amino acids adopts a cyclic conformation at low temperatures. [Allison, S., et al., J. Sep. Sci. 2010, 33, 2430- 2438.]
Conformational Bias in 2'-Selenium-Modified Nucleosides and the Effect on Helical Structure and Extracellular Recombinant Protein Production: Current Systems and Applications
Creators: name: Thompson, Richard
Publisher: name: Georgia State University
Year: 2011

description: Part One. X-ray crystallography has benefited from the synthetic introduction of selenium to different positions within nucleic acids by easing the solving of the phase problem. Interestingly, its addition to the 2' position of the ribose ring also significantly enhances crystal formation. ˜This phenomenon was investigated to describe the effect of selenium-based and other 2' modifications to the ribose ring of nucleosides in solution, as well as the incorporation of the selenium-modified nucleotides into a helical structure. This work correlates the difference in conformation propensity between the selenium containing nucleosides and oligomers towards a rationale behind the enhanced crystal forming behavior. Part Two. Recombinant protein production is a critical tool in laboratories and industries, and inducing extracellular transport of these products to the culture medium shows potential for improving cases where the yields are not sufficient in quality or quantity. This review incorporates current practices and systems with future perspectives.
DNA Photocleavage by 9-Aminomethylanthracene Dyes at pH 7.0:  Ionic Strength Effects
Creators: name: Deeyaa, Blessing
Publisher: name: Georgia State University
Year: 2011

description: DNA photosensitizers are compounds that are capable of binding in to DNA strands through groove binding, intercalation, or electrostatic interactions.  Excitation of these agents by light generates reactive oxygen species which causes extensive photo-oxidative damage to genomic DNA.  Physiological concentrations of NaCl and KCl are ~ 150 mM and 260 mM within the cell nucleus where DNA is contained.  Unfortunately, the ability of most photosensitizers to bind to double-helical DNA is reduced and photocleavage yields are diminished as concentrations of salt increase. The aim of this project is to observe the photocleavage of pUC19 plasmid DNA induced by N1,N1-bis(9-anthrymethyl)triethylenetetraamine tetrahydrochloride (AL-VIII 23) 1 or N,N-dimethyl-N?-(9-methylanthracenyl)ethylenediamine (NMEA) 2 in presence of salt.  Spectroscopic titrations and DNA melting assays were used to study binding modes and affinities of both dyes to the helix upon the addition of salt.
Cyanine Dye Interactions with Quadruplex and Duplex DNA: Changes in Conformation, Stability, and Affinity
Creators: name: Mickelson, Leah
Publisher: name: Georgia State University
Year: 2011

description: There is a high demand for quadruplex-specific compounds that not only bind preferentially to quadruplex DNA over duplex DNA, but also bind to one quadruplex motif over other motifs.  Quadruplex structures are recognized as common occurrences in cancer cells, and if a compound could stabilize this structure, it may serve as an effective anti-cancer treatment with minimal side effects.  In this study, cyanine dyes? interactions with DNA were analyzed with fluorescence titrations, UV-Vis thermal studies, circular dichroism titrations, and surface plasmon resonance (SPR) analysis.  With these techniques, binding affinity, DNA stabilization, and conformational shifts were analyzed to determine if cyanine dyes could act as quadruplex-specific binding compounds for possible cancer treatments.
A FRAMEWORK FOR LOCALIZATION OF OPEN SOURCE APPLICATIONS FOR INDIGENOUS ETHIOPIAN LANGUAGES: A CASE STUDY ON AMHARIC
Creators: name: ABUBEKER SEID ALI
Publisher: name: Zenodo
Year: 2024

description: A FRAMEWORK FOR LOCALIZATION OF OPEN 

SOURCE APPLICATIONS FOR INDIGENOUS 

ETHIOPIAN LANGUAGES: A CASE STUDY ON

AMHARIC
Novel Rhein Analogues as Potential Anicancer Agents and a Novel Metal Free Synthesis of 6H-ISOINDOLO[2,1-A]INDOL-6-ONE
Creators: name: Draganov, Alexander
Publisher: name: Georgia State University
Year: 2011

description: The first section of this work describes the synthesis of a library of novel rhein analogues that are potential anticancer agents. The design of these compounds takes advantage of the ability for rhein to intercalate into DNA and as the incorporation of an alkylating agent, which serves to covalently modify DNA. In three cell lines, these compounds showed potent cytotoxicity with IC50 in the low to mid-?M range. The second project was focused on the development of an efficient synthesis of 6H-Isoindolo[2,1-…]indol-6-one (24), a core structure for a number of biologically active compounds. The approach is metal-free and uses a Beckmann rearrangement followed by an intramolecular cyclization.
SDG102, a H3K36-Methyltransferase-Encoding Gene, Plays Pleiotropic Roles in Growth and Development of Maize (Zea mays L.)
Creators: name: Li, Yongjian
name: Sun, Weifeng
name: Wang, Zhenhui
name: Wan, Chang
name: Zhang, Jun
name: Qi, Xin
name: Zhang, Jian (Professor Of Biology)
Publisher: name: Multidisciplinary Digital Publishing Institute
Year: 2022

description: Although histone lysine methylation has been studied in thale cress (Arabidopsis thaliana (L.) Heynh.) and rice (Oryza sativa L.) in recent years, its function in maize (Zea mays L.) remains poorly characterized. To better understand the function of histone lysine methylation in maize, SDG102, a H3 lysine 36 (H3K36) methylase, was chosen for functional characterization using overexpressed and knockout transgenic plants. SDG102-deficiency in maize caused multiple phenotypes including yellow leaves in seedlings, late-flowering, and increased adult plant height, while the overexpression of SDG102 led to reduced adult plant height. The key flowering genes, ZCN8/ZCN7 and MADS4/MADA67, were downregulated in SDG102-deficient plants. Chromatin immunoprecipitation (ChIP) experiments showed that H3 lysine 36 trimethylation (H3K36me3) levels were reduced at these loci. Perturbation of SDG102 expression caused the misexpression of multiple genes. Interestingly, the overexpression or knockout of SDG102 also led to genome-wide decreases and increases in the H3K36me3 levels, respectively. Together, our results suggest that SDG102 is a methyltransferase that catalyzes the trimethylation of H3K36 of many genes across the maize genome, which are involved in multiple biological processes including those controlling flowering time.
Binding of Bisbenzamidines with AT Rich DNA: A Thermodynamic Study
Creators: name: Kilpatrick, Nancy
Publisher: name: Georgia State University
Year: 2011

description: Diamidines are small molecules that generally possess antiparasitic properties and bind preferentially to the minor groove of AT rich DNA.  With the goal of getting a better understanding of the thermodynamic driving forces and binding affinities, a series of pentamidine analogs were investigated with various AT rich DNA by ITC, UV-Vis and fluorescence spectroscopic methods.  Findings suggest that the substitution of the linker oxygen of pentamidine to a nitrogen slightly improves the binding affinity.  All of the investigated compounds are entropically driven at 25 oC with non-alternating AT DNA.  Additionally, the increased fluorescence of the nitrogen and sulfur linked analogs will enable future work to be done with fluorescence microscopy to help determine if and where these compounds accumulate in the target organism.
Optimization of Expression and Purification Methods for the Study of Protein-Based Magnetic Resonance Imaging Contrast Agents
Creators: name: White, Natalie
Publisher: name: Georgia State University
Year: 2011

description: Magnetic Resonance Imaging instruments rely on a contrast agent to provide high-resolution images of tissues in vivo. However, current clinical contrast agents are hindered by low relaxivity and fast correlation time, necessitating high injection dosages. These concerns, among others, have driven the development of a class of protein-based contrast agents (ProCAs), by design of lanthanide binding sites into a scaffold protein. ProCA1 has a higher reported relaxivity and dosage efficiency than current contrast agents.  In this study, expression and Glutathione-S-Transferase purification procedures were optimized, and a refolding method for rapid production of ProCA1 has been developed to enable studies of conformation, metal binding, relaxivity, and in vivo applications. Several ProCA1 variants with 4-5 charged ligand residues were shown to have strong gadolinium binding affinity (Kd of 10-12 M) and metal selectivity. Several options to improve ProCA1 have been explored, including addition of a polyethylene chain or a bombesin tag.
Interactions of Metals and Radicals: A Biochemical Perspective in Tryptophan Dioxygenase
Creators: name: Dornevil, Kednerlin
Publisher: name: Georgia State University
Year: 2011

description: An intriguing mystery about tryptophan 2, 3-dioxygenase is its hydrogen peroxide-triggered enzyme reactivation from the resting ferric oxidation state to the catalytically active ferrous form. In this study, we found that such an odd Fe(III) reduction by an oxidant depends on the presence of L-Trp,  which  ultimately serves as the reductant for the enzyme. In the peroxide reaction with tryptophan 2, 3-dioxygenase, a previously unknown catalase-like activity was detected. A ferryl species (‰ = 0.055 mm/s and ?EQ = 1.755 mm/s) and a protein-based free radical (g = 2.0028 and 1.72 millitesla linewidth) were characterized by M?ssbauer and EPR spectroscopy, respectively. This is the first compound ES-type of ferryl intermediate from a heme-based dioxygenase characterized by EPR and M?ssbauer spectroscopy. Density functional theory calculations revealed the contribution of secondary ligand sphere to the spectroscopic properties of the ferryl species. A Trp-Trp dimer and a monooxygenated L-Trp were both observed as the enzyme reactivation by-products by mass spectrometry. Together, these results lead to the unraveling of an over 60-year old mystery of peroxide reactivation mechanism.
Synthesis and Characterization of Metal Nanoclusters Stabilized by Dithiolates
Creators: name: Robinson, Donald
Publisher: name: Georgia State University
Year: 2011

description: Rapidly expanding research in nanotechnology has led to exciting progress in a versatile array of applications from medical diagnostics to photocatalytic fuel cells. Such success is due to the ability of researchers to manipulate the desired properties of nanomaterials by controlling their size, shape, and composition. Among the most thriving areas of nanoparticle research has been the synthesis and characterization of stable metallic nanoclusters capped by thiolate ligands. Our group has extended this research to study copper, silver, and gold clusters with remarkable stability and energetics, which was achieved by using dithiolates as the ligand stabilizers. In addition to the enhanced stability offered by the chelate effect, the use of dithiolate ligands instead of monothiolates is proposed to provide an alternate interfacial bond structure that is shown to strongly influence energetic properties of nanoclusters, with strong evidence of metal-ligand charge transfer. Energetic properties were characterized by spectroscopic and electrochemical methods.
title: Carbon Capture, Usage and Storage - SCCS evidence to the Business, Energy & Industrial Strategy Committee
Creators: name: Bell, Rebecca
name: Brownsort, Peter
name: Chalmers, Hannah
name: Haszeldine, R Stuart
name: Lucquiaud, Mathieu
name: Mackay, Eric
name: Parmiter, Philippa
name: Viguier, Romain
Publisher: name: SCCS
Year: 2018
Subjects: subject: CCS
subject: carbon capture and storage
subject: CCUS
subject: Business, Energy & Industrial Strategy Committee

description: • Carbon capture and storage (CCS) is essential for the UK to meet its carbon emissions reduction targets to 2050. • Furthermore, CCS is essential to meet the Paris Agreement goal of keeping global average temperature rise well below 2°C. • CCS means that jobs in high-emitting industries can be retained in the UK; without CCS those industries will have to cease operation as emissions budgets tighten. • The urgent need to deploy CCS at scale should outweigh targets for cost reduction. • The UK is uniquely placed to develop carbon dioxide (CO₂) storage – failure to make use of the offshore geological resource could be construed as a waste of public resource. • CO₂ usage may have a role to play in driving the development of carbon capture, but it is not a substitute for development of permanent geological storage.
description: • Carbon capture and storage (CCS) is essential for the UK to meet its carbon emissions reduction targets to 2050. • Furthermore, CCS is essential to meet the Paris Agreement goal of keeping global average temperature rise well below 2°C. • CCS means that jobs in high-emitting industries can be retained in the UK; without CCS those industries will have to cease operation as emissions budgets tighten. • The urgent need to deploy CCS at scale should outweigh targets for cost reduction. • The UK is uniquely placed to develop carbon dioxide (CO₂) storage – failure to make use of the offshore geological resource could be construed as a waste of public resource. • CO₂ usage may have a role to play in driving the development of carbon capture, but it is not a substitute for development of permanent geological storage.
Synthesis of Selective 5-HT7 Receptor Antagonists
Creators: name: Ehalt, Adam
Publisher: name: Georgia State University
Year: 2011

description: The 5-HT7 receptor is the most recent addition to the 5-HT receptor family and has been linked to a variety of physiological and pathophysiological processes. Well established antide-pressant pharmaceuticals have recently been found to activate the 5-HT7 receptor, supporting the role of the 5-HT7 receptor in the antidepressant mechanism. The synthesis of potent selec-tive 5-HT7 receptor antagonists could afford a greater understanding of the 5-HT7 receptor function as well as lead to potential drug candidates.
The synthesis of unfused biheteroaryl derivatives as 5-HT7 receptor ligands has been de-scribed within. These compounds have been tested for biological activity on the 5-HT6 and 5-HT7 receptors. 4-(3?-Furyl)-2-(N-substituted-piperazino)pyrimidines were found to be potent 5-HT7 receptor ligands. 4-(2?-Furyl)-2-(N-substituted-piperazino)pyrimidines have shown high se-lectivity for the 5-HT7 receptor over the 5-HT6 receptor.
Arylboronic Acids With Strong Fluorescence Intensity Changes Upon Sugar Binding
Creators: name: Laughlin, Sarah
Publisher: name: Georgia State University
Year: 2011

description: Boronic acids play an important role in the design and synthesis of chemosensors for carbohydrates due to their ability to reversibly bind with diol-containing compounds. Along this line, the availability of boronic acids that change fluorescence upon sugar binding is critical to a successful sensor design effort. Here, two boronic acids that show strong fluorescent intensity changes upon sugar binding are reported: isoquinoline-7-boronic acid (7-IQBA) and phenoxathiin-4-boronic acid (4-POBA).