Digital Commons Network^™

Synthesis And Evaluation Of Stimulatory Properties Of Glycolipids For Natural Killer T Cells, Xiangtian Long

Theses and Dissertations

Natural killer T cells (NKT cells) are a subset of T cells. They regulate a wide range of diseases including infection, tumor growth, and autoimmune diseases, through recognizing glycolipid antigens in the context of CD1d. An understanding of the scope of glycolipid antigens would facilitate use of this cell type in controlling immune responses. Till today, a lysosomal glycolipid, isoglobotrihexosylceramide (iGb3), is the only natural glycolipid that has been found to be recognized by both human and mouse NKT cells. To elucidate the molecular basis of this specific recognition, iGb3 variants were designed and prepared: i) replacement of the C26 …

Center Of Ecological Studies Feasibility Project, Suzanne Williams, Jill Leonard

Grant

No abstract provided.

Electron Transport And Sensor Characteristics Of Tin Dioxide Based Nanocrystalline Materials, Allen Chaparadza

Dissertations and Theses

Wide band gap, transparent semiconductor Sn0₂ is an n-type conductor and is widely used as a sensor material as well as transparent electrode material e.g. in solar cells and flat panel displays. Recent discovery of p-type doping with Li has opened exciting possibilities in new classes of sensors and transparent nanoelectronic devices. Li-doping in SnO₂ nanoparticles was explored through a gel-sol method of synthesis to examine the influence of reaction conditions such as pH, dopant concentration, and calcination temperature. The Li doping in nanoparticles was characterized using nuclear reaction analysis and the nanostructure with high-resolution electron transmission microscopy …

Coexistence And Transition Between Cassie And Wenzel State On Pillared Hydrophobic Surface, Takahiro Koishi, Kenji Yasuoka, Shigenori Fujikawa, Toshikazu Ebisuzaki, Xiao Cheng Zeng

Xiao Cheng Zeng Publications

Water droplets on rugged hydrophobic surfaces typically exhibit one of the following two states: (i) the Wenzel state [Wenzel RN (1936) Ind Eng Chem 28:988–994] in which water droplets are in full contact with the rugged surface (referred as the wetted contact) or (ii) the Cassie state [Cassie, ABD, Baxter S (1944) Trans Faraday Soc 40:546–551] in which water droplets are in contact with peaks of the rugged surface as well as the “air pockets” trapped between surface grooves (the composite contact). Here, we show large-scale molecular dynamics simulation of transition between Wenzel state and Cassie state of water droplets …

Impact Of Flash Animation In Learning Concepts Of Matter Among Elementary Students, Rhodora S. Santos

Theses and Dissertations - UTB/UTPA

This study examines the instructional effect of flash animation on students' achievement in learning specific concepts of matter. The subjects used in this study were 5th-grade students of the researcher from Dan Ramirez Elementary. Each class or section of these students was randomly assigned as the control group (n = 20) and the experimental group (n =20). The subjects in the control group were exposed to traditional textbook reading while the subjects in the experimental group were exposed to flash animation. To measure the students' achievement from the concepts learned, a pre-test and a post test were both administered to …

Investigation Of Photophysical And Photochemical Processes In Conjugated Polymer Nanoparticles By Single Particle And Ensemble Spectroscopy, Craig Szymanski

All Dissertations

Single molecule imaging has emerged as a powerful tool in a range of applications, but the field is limited by a lack of fluorescent probes with sufficient brightness and photostability for many demanding applications such as tracking of single biomolecules in cells and tissues at video rate with 1 nm spatial resolution. Conjugated polymers hold great promise as a solution to these issues, with a high density of π electrons and variety of chemistries, allowing efficient and tunable absorption of light. This dissertation describes the development and characterization of a novel type of nanoparticle composed of conjugated polymer called CPdots. …

Developmental Expression Of Xenopus Myosin 1d And Identification Of A Myo1d Tail Homology That Overlaps Th1, Janine M. Leblanc-Straceski, Anna Sokac, William Bement, Pablo Sobrado, Laura Lemoine

Chemistry Faculty Research & Creative Works

Xenopus laevis myosin 1d (XlMyo1d) is a member of the myosin I class, subclass 4. Members of this class are single headed, bind calmodulin light chains and have lipid binding domains in their tails. The rat myo1d homologue has been implicated in endosome vesicle recycling in epithelial cells. Mutations in the Drosophila myosin 1d homologue cause situs inversus in the abdomen. The XlMyo1d cDNA has been cloned and the derived amino acid sequence is 80% identical to the rat and human homologues. Sequence comparison revealed a novel isoform-specific tail homology embedded in the Tail Homology 1 (TH1) domain characteristic of …

Detecting Organic Molecules On The Surface Of Inorganic Dust Particles Using Aerosol Mass Spectrometry, Sileola B. Akinsiku

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Detection of organic molecules present on the surface of dust particles is important in homeland security, agriculture, and several other applications. The research presented reports the ability of the aerosol mass spectrometer (AMS) to detect molecules on the surface of dust particles without detecting the particle core.

Experiments were carried out to detect semi-volatile organic compounds adsorbed onto the surface of particulates without interference from the dust particle core. Methyl salicylate, oleic acid, and organophosphorus pesticides such as Malathion were detected on the surface of particles representative of dust-type materials. Zeolite powders were used as aerosol support, representative of a …

A Comparative Study Of The Structural Features And Kinetic Properties Of The Mofe And Vfe Proteins From Azotobacter Vinelandii, Miguel Alejandro Pabon Sanclemente

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Biological nitrogen fixation is accomplished in the bacterium Azotobacter vinelandii by means of three metalloenzymes: The molybdenum, vanadium, and iron-only nitrogenase. The knowledge regarding biological nitrogen fixation has come from studies on the Mo-dependent reaction. However, the V- and Fe-only-dependent reduction of nitrogen remains largely unknown.

By using homology modeling techniques, the protein folds that contain the metal cluster active sites for the V- and Fe-only nitrogenases were constructed. The models uncovered similarities and differences existing among the nitrogenases regarding the identity of the amino acid residues lining pivotal structural features for the correct functioning of the proteins. These differences, …

Carbohydrate Derivatives In Antibiotics Research, Yi Liang

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In this study, we investigated the potential applications of carbohydrates in the development of new antibiotics. To tackle the problem of multidrug-resistant variants of M. tuberculosis (MDR-TB), we investigated the biosynthesis pathways of trehalose, which has contributed to significant drug resistance. Some new methods were developed for the synthesis of potential inhibitors (6-azido-trehalose and 6,6'-diazido-trehalose) that have been designed to imitate the intermediate molecule (trehalose 6-phosphate, TPP) of OtsA-OtsB pathway. At the same time, some new antibacterial agents based on trehalose have been synthesized. Members of the 1,2,3-triazole family have shown interesting biological properties. Steroid derivatives have been developed in …

Identifying Biomarkers For Resistance To Novel Cisplatin Analogues In Human Lung, Breast And Prostate Cancers, Becky Michelle Hess

UNLV Theses, Dissertations, Professional Papers, and Capstones

Cisplatin is a common therapeutic agent used in cancer treatment. Unfortunately, resistance to cisplatin in addition to severe side effects limits its use in cancer treatment. Two novel cisplatin analogues, 4DB and 4TB were shown to have varying cytotoxicity in lung, breast and prostate cancer cells. The hypothesis for this study states that the differences in 4DB and 4TB cytotoxicity among different tissue types is due to the type and efficiency of DNA repair mechanisms involved in response to these drugs.

To test the hypothesis, proteins involved in the rate limiting step of nucleotide excision repair (NER) and mismatch repair …

Water Quality Changes In A Constructed Wetland At The Springs Preserve In Las Vegas, Nevada, Aaron Mathis Miller

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Springs Preserve near downtown Las Vegas, Nevada contains a seven-acre constructed wetland. Springs Preserve managers are planning to use water from the constructed wetland to irrigate creeks immediately north of the wetland. These creeks will be used by a variety ofaquatic wildlife, including endangered amphibians sensitive to harmful metalloids, such as selenium, lead, and arsenic.

In an attempt to answer toxicological questions about contaminant concentrations in the constructed wetland, three metals and metalloids (selenium, arsenic, and lead), two nutrients (nitrogen and phosphorus), and the major ionic species were analyzed at four sampling locations for aqueous concentrations, in two separate …

Design, Synthesis, And Film Formation Of Fluorine Containing Colloidal Dispersions, Anuradha Misra

Dissertations

Fluoropolymers (FPs) have been subject of interest for many years, however due to extreme synthetic and processing conditions their applications have been limited. This dissertation focuses on design and synthesis of fluorine containing colloidal dispersions to advance limited knowledge and to gain further understanding of fluorine containing colloidal dispersions. Fluoroacrylates and fluoro methacrylates consisting of varying chain length of perfluoroalkyl side chain were copolymerized with methylmethacrylate (MMA) and n-butylacrylate (n-BA) under aqueous environment utilizing phospholipids (PLs) as dispersing agent. Morphologies of colloids, coalescence, and film formation processes after water evaporation was investigated using various microscopic probes such as transmission electron …

The Synthesis And Characterization Of Novel Microporous Hybrid Organic/Inorganic Materials, Kelly Whitenack

Renée Crown University Honors Thesis Projects - All

Inorganic chemistry is essential to the formulation and improvement of modern materials such as catalysts, semiconductors, optical devices, super conductors, and advanced ceramic materials.¹ New areas of inorganic chemistry are constantly being explored and new and often unusual inorganic compounds are constantly being synthesized and identified.¹ Recently the field of inorganic chemistry has witnessed the synthesis and characterization of microporous metal organic framework compounds (MOFs). Microporous organic/inorganic materials have a wide range of physical properties as well as applications. The physical properties and applications drive the investigation into the synthesis and discovery of new and useful hybrid MOF …

Rational Design And Synthesis Of Multifunctional Nanostructures For Biological And Medicinal Applications, Amy N. Otuonye

Renée Crown University Honors Thesis Projects - All

Mobile Composite Material (MCM-41) was modified by the addition of various functional groups, which increase the materials’ efficiency for an assortment of applications. Mesoporous materials have demonstrated to be capable of adsorbing and releasing of model drug molecules, rhodamine 6G and ibuprofen. Mesoporous silica materials functionalized with mercaptopropyltrimethoxysilane (MPTS), vinyltrimethoxysilane (VTS), aminopropyltrimethoxysilane (APTS), and N-(2-animoethyl)-3-aminopropyltriethoxysilane (AAPTS) were used to test the adsorption and release of rhodamine 6G (R6G) and ibuprofen. The vinyl and mercaptopropyl groups adsorbed and released more rhodamine 6G than the primary and secondary amine groups. The adsorption and release of ibuprofen was the opposite of the R6G …

Completing Chemistry Taks Objective 4(9d): The Effect Of Flash Animation, Judith B. Dano

Theses and Dissertations - UTB/UTPA

This study examines the effect of flash animation on learning effectiveness. The main goal of the study was to verify if using flash animation on learning chemistry concepts particularly Chemistry TAKS Objective 4 (9D) will have an impact on students learning achievement. The subjects in this study were 10th grade students from PSJA Memorial High School. Two class sections were randomly assigned as the treatment group each with 20 subjects (n=40) and another two class sections were assigned as the control group (n=40). The treatment group was exposed to flash animation while the control group had the traditional lecture type …

Methyl Septanoside Hydrolysis As A Measure Of Carbohydrate Ring Flexibility: Substrate Synthesis And Kinetics Analysis, Shawn Michael Miller

Honors Scholar Theses

A number of seven-membered ring systems have been found to have promising enzyme inhibiting properties. The common explanation for their efficacy is the apparent improved flexibility that the ring-system has over smaller rings. In an attempt to probe the validity of this hypothesis, unnatural seven-membered ring carbohydrates have been generated and subjected to kinetics analysis using hydrolysis. In particular, methyl α- and β-D-glycero-D-guloseptanoside were subjected to acid-catalyzed hydrolysis and monitored via HNMR experiments. The rate constants of the reactions were determined and compared to the hydrolysis rate constants of comparable pyranose carbohydrates and found to be significantly faster, indicating an …

Functional Characterization And Assembly Studies Of Carboxysomes In Halothiobacillus Neapolitanus, Zhicheng Dou

Dissertations

Functional characterization and assembly studies of carboxysomes in Halothiobacillus neapolitanus were pursued in order to understand the roles of carboxysomes in the carbon metabolism in H. neapolitanus and the assembly of carboxysomes in vitro and in vivo. Previously, a low abundance H. neapolitanus carboxysomal protein, CsoSCA was identified as a novel carboxysomal shell-bound carbonic anhydrase. The enzyme is thought to dehydrate the cytosolic bicarbonate to CO2, the substrate of the RuBisCO packaged within the carboxysome [14, 21]. In this study, the carboxysomal shell was identified as a diffusion barrier for CO2 and O2 molecules. The shell-bound CsoSCA protein facilitates the …

Molecular Interactions Involved In The Biogenesis Of Bacterial Microcompartments, Balaraj Balaram Menon

Dissertations

This study was undertaken with the goal of gaining better insights into the assembly pathway of carboxysomes and related polyhedra. Aside from their similarity in size and shape, all known microcompartments package enzymes that mediate key reactions of metabolic pathways [1]. It remains unclear whether the sequestered enzymes participate in microcompartment assembly and/or contribute to the overall shape of the polyhedra. Genetic studies in Salmonella enterica have suggested that the shells of organelles involved in propanediol utilization assemble in the absence of encapsulated enzymes [2]. In this study, in vivo yeast two-hybrid screens, involving components of the ethanolamine utilization (Eut) …

Synthetic Studies Of Laulimalide Analogues, Ian Addison Mcalexander

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Chapter 1 provides some background information on the disease area of cancer and current modes of treatment. Chemotherapy treatment is discussed with a focus on the major cellular targets for these drugs: DNA and microtubules. For each target, classes of active compounds are described along with their mode of action. The microtubule stabilizing agent laulimalide is introduced and a case is made for analogue synthesis.

Chapter 2 describes our first generation efforts toward synthesis of des-methyl laulimalide. The target compound is divided into a northern and southern fragment with the synthesis of each fragment described. The preparation of landmark intermediates …

Sonication Assisted Synthesis Of Oligomannosides, Christabel Tomla Tanifum

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Oligomannosides prevalently exist as cell surface antigens. They play important roles in diseases such as viral infection and cancer, and they have been shown to be useful as candidates for vaccines. HIV, one of the most devastating modern diseases, has a high content of mannose sugars on its envelope glycoprotein gp120. Oligomannosides of the HIV virus, also called Man9, which are found on the glycoprotein gp120, have been shown to play a protective role for the HIV virus, shielding highly conserved protein domains of gp120 from proteolytic attacks. Thus gp120 plays an important role in HIV infection of cells, being …

Breaking The Spell: Developing A New Generation Of Porphyrins For Treating Cerebral Tumors, Ryan Harrison Gray

Honors Capstones

No abstract provided.

Specific And Non-Specific Binding Of Proteins And Nucleic Acids On Chemically Modified Reticulated Vitreous Carbon Electrodes, Hemangi Shedge

All Theses

Proteins and nucleic acids play major roles in many important biological processes. Specific and rapid detection of these biomolecules is important for early and precise diagnosis of various genetic diseases and other medical conditions. However, accurate and inexpensive detection of proteins and nucleic acids has always been a challenge. One of the obstacles is their non-specific adsorption on the sensor surface which leads to the conformational changes in the proteins, sometimes causing their denaturation. The non-specific adsorption on the surface also leads to sensor fouling which induces changes in the availability of active sensor surface for detection of analytes and …

Synthesis Of Ionic Liquid Monomers Using Fluorinated Sulfonyl Imide Anions And The 1,3-Dialkylimidazolium Cation, Thomas Hickman

All Dissertations

With their unique material and solvent properties, ionic liquids have seen an amazing, exponential increase in interest. After a brief introduction of select areas of interest for these compounds, this thesis mainly focuses on the development of novel polyfunctional ionic liquids and polymeric ionic liquids.
One of the preferred anions for ionic liquids is the bis((trifluoromethyl)sulfonyl) imide anion, first introduced by our group in 1982. It shows excellent thermal stability and the desired resonance delocalization of a negative charge for ionic liquids. A series of monofunctional, difunctional, and multi-functional bis(perfluoroalkylsufonyl)imides, along with 1,3-dialkylimidazolium cations were prepared by direct methylation of …

Analyzing The Binding Of Co(Ii)-Specific Inhibitors To The Methionyl Aminopeptidases From Escherichia Coli And Pyrococcus Furiosus, Sanghamitra Mitra, George Sheppard, Jieyi Wang, Brian Bennett, Richard C. Holz

Chemistry Faculty Research and Publications

Methionine aminopeptidases (MetAPs) represent a unique class of protease that is capable of the hydrolytic removal of an N-terminal methionine residue from nascent polypeptide chains. MetAPs are physiologically important enzymes; hence, there is considerable interest in developing inhibitors that can be used as antiangiogenic and antimicrobial agents. A detailed kinetic and spectroscopic study has been performed to probe the binding of a triazole-based inhibitor and a bestatin-based inhibitor to both Mn(II)- and Co(II)-loaded type-I (Escherichia coli) and type-II (Pyrococcus furiosus) MetAPs. Both inhibitors were found to be moderate competitive inhibitors. The triazole-type inhibitor was found to …

Information-Theoretical Analysis Of Time-Correlated Single-Photon Counting Measurements Of Single Molecules, David Talaga

Department of Chemistry and Biochemistry Faculty Scholarship and Creative Works

Time-correlated single photon counting allows luminescence lifetime information to be determined on a single molecule level. This paper develops a formalism to allow information theory analysis of the ability of luminescence lifetime measurements to resolve states in a single molecule. It analyzes the information content of the photon stream and the fraction of that information that is relevant to the state determination problem. Experimental losses of information due to instrument response, digitization, and different types of background are calculated and a procedure to determine the optimal value of experimental parameters is demonstrated. This paper shows how to use the information …

Spectroscopic Characterizations Of The Compound Ii Intermediate Of Soybean Peroxidase From Soybean Seed Coatings, Andoh-Baidoo Rosemarie Agyepong

Theses and Dissertations

Spectroscopic characterization of ferric soybean peroxidase with peroxides were studied to determine the ligand coordination and to characterize the structure of the heme active site and its intermediates (ferryl species). The lifetime, chemical reactivity and distinctive colors of the ferryl species (FeIV) formed during the oxidation of peroxidase (FeIII) by peroxides enabled structure, dynamics and reaction mechanisms to be studied. Resonance Raman spectroscopy was used as a means of characterizing the structure of the soybean peroxidase and its intermediates. Excitation in the Soret absorption band at 406.7nm with 2-5mW laser power was used for this study. Resonance Raman spectra in …

Ionic Selectivity In L-Type Calcium Channels By Electrostatics And Hard-Core Repulsion, Dezso Boda, Douglas Henderson, Monika Valisko, Bob Eisenberg, Dirk Gillespie

Faculty Publications

A physical model of selective "ion binding" in the L-type calcium channel is constructed, and consequences of the model are compared with experimental data. This reduced model treats only ions and the carboxylate oxygens of the EEEE locus explicitly and restricts interactions to hard-core repulsion and ion–ion and ion–dielectric electrostatic forces. The structural atoms provide a flexible environment for passing cations, thus resulting in a self-organized induced-fit model of the selectivity filter. Experimental conditions involving binary mixtures of alkali and/or alkaline earth metal ions are computed using equilibrium Monte Carlo simulations in the grand canonical ensemble. The model pore rejects …

Accelerated Oxidation Of Epinephrine By Silica Nanoparticles, Zhimin Tao, Gang Wang, Jerry Goodisman, Tewodros Asefa

Chemistry - All Scholarship

We have measured the influence of mesoporous silica (MCM-41 and SBA-15) nanoparticles and dense silica nanoparticles on epinephrine oxidation, a pH-dependent reaction, whose rate is small in acidic or neutral solutions but much greater at higher pH. The reaction was measured by monitoring adrenochrome at 480 nm, the product of epinephrine oxidation. In distilled water (dH ₂O) with no particles present, the oxidation of epinephrine occurs slowly but more rapidly at higher pH. The presence of MCM-41 or silica spheres does not accelerate the oxidation, but SBA-15 does, showing that the difference in the structures of nanomaterials leads to …

Liquid Carbon Dioxide Extraction Of Various Food Flavors: Evaluation And Analysis, Deven Lee Shinholt

Undergraduate Honors Thesis Collection

Sub- and supercritical carbon dioxide has been utilized as an extraction solvent for a variety of natural compounds. This requires the use of specialized high-pressure vessels. It was reported recently that common laboratory apparatus (centrifuge tubes) could be utilized in liquid carbon dioxide extractions obviating the need for specialized equipment. Various herbs and spices (including orange, lemon, lime, and grapefruit zest, oregano, rosemary, sage, spearmint, nutmeg, black peppercorns, cloves, caraway seeds, and vanilla beans) were used as substrates for liquid carbon dioxide extractions by this straightforward technique. The extracted oils, containing terpenes and terpenoids, were then analyzed through GC/MS. Liquid …