Chemistry Commons^™

Photocrosslinking Probes Proximity Of Thymine Modifiers Tethering Excitonically Coupled Dye Aggregates To Dna Holliday Junction, Shibani Basu, Keitel Cervantes-Salguero, Bernard Yurke, William B. Knowlton, Jeunghoon Lee, Olga A. Mass

Chemistry and Biochemistry Faculty Publications and Presentations

A DNA Holliday junction (HJ) has been used as a versatile scaffold to create a variety of covalently templated molecular dye aggregates exhibiting strong excitonic coupling. In these dye-DNA constructs, one way to attach dyes to DNA is to tether them via single long linkers to thymine modifiers incorporated in the core of the HJ. Here, using photoinduced [2 + 2] cycloaddition (photocrosslinking) between thymines, we investigated the relative positions of squaraine-labeled thymine modifiers in the core of the HJ, and whether the proximity of thymine modifiers correlated with the excitonic coupling strength in squaraine dimers. Photocrosslinking between squaraine-labeled thymine …

A New Class Of Antibiotic That Prevents Drug Tolerance, Persistence, And Resistance By Controlling Emergence Of Phenotypes., Pankaj Dinkar Patil

Dissertations - ALL

The fight against bacterial infections and innovations in antibiotic therapy has never halted throughout human history. However, bacteria have evolved smartly and resistance against practically all conventional antibiotics has been developed. Furthermore, bacteria can form biofilms, which are surface-attached multicellular colonies. Biofilms shield bacteria against antibiotics and makes it harder to entirely eradicate infections . Under antibiotics stress, bacteria evolve into different phenotypes like hyper motile, hyper adherent and hyper virulent which are tolerant and persistent to antibiotic treatment. The use of antibiotic therapy to combat such resilient bacterial phenotypes is extremely tough. As a result, the scientific community is …

Taking Action: Managing Inclusive Excellence In Academia, Lesley Ann Giddings, Christine Salomon

Chemistry: Faculty Publications

No abstract provided.

Properties And Behavior Of Tricarbonyl Manganese Scorpionate Complexes, Billy Shone

Master's Theses (2009 -)

Manganese tricarbonyl complexes have widely been studied for their ability to release carbon monoxide (CO) in the presence of light for potential applications in cancer therapy and in catalysis. Most studies focus on the kinetics and quantity of CO release and the overall impact on cell death. Far fewer studies identify the manganese intermediates and final products after decarbonylation. Identification of such products would be critical to improving reactivity and understanding potential (undesirable) side effects in future applications employing these CO releasing molecules (CORMs). Recently, nitrogen confused C-scorpionate ligands were introduced by the Gardinier group where a pyrazolyl ring is …

The Development Of A Monolithic Spatial Heterodyne Spectrometer For Extreme Environments, Arelis Michelle Colόn

Theses and Dissertations

This work describes improvements to a novel instrument, the monolithic spatial heterodyne Raman spectrometer (mSHRS), which has potential to be utilized in space exploration and deep-ocean marine sensing. In previous work, the spatial heterodyne Raman spectrometer (SHRS) was demonstrated, as a small, high resolution, wide field of view spectrometer, originally developed for space applications where small size and compactness is a key consideration or where a wide field of view is advantageous, such as in remote spectroscopy. The spatial heterodyne spectrometer (SHS) was then later utilized for remote Laser-Induced Breakdown Spectroscopy (LIBS). The high throughput, high spectral resolution, and large …

Pyridyl Bis-Urea Macrocycles As Supramolecular Synthons And The Design And Synthesis Of Small Molecule Pharmaceuticals Targeting Ly6k, Devan D. Buchanan

Theses and Dissertations

Assembled pyridyl bis-urea macrocycles have been utilized as 1D supramolecular synthons to construct hierarchical assemblies. These macrocycles have both urea and pyridyl functional groups and can form non-covalent interactions with hydrogen or halogen bond donors through symmetric, ditopic acceptor motifs. Bis-urea macrocycles offer interesting capabilities as synthons to organize donors into well-defined crystal structures. In part, this is due to the urea motifs’ propensity to assemble through hydrogen bonding. New, asymmetric pyridyl macrocycles were synthesized, crystallized, and experimentally probed to determine how symmetry affects their assembly and utility as supramolecular synthons.

The Uphadhyay group identified small molecules, including NSC11150, …

Developing A Rational Approach To Designing Recombinant Proteins For Peptide-Directed Nanoparticle Synthesis, Adithya Polasa, Imann Mosleh, James Losey, Alireza Abbaspourrad, Robert Beitle, Mahmoud Moradi

Chemistry & Biochemistry Faculty Publications and Presentations

The controlled formation of nanoparticles with optimum characteristics and functional aspects has proven successful via peptide-mediated nanoparticle synthesis. However, the effects of the peptide sequence and binding motif on surface features and physicochemical properties of nanoparticles are not well-understood. In this study, we investigate in a comparative manner how a specific peptide known as Pd4 and its two known variants may form nanoparticles both in an isolated state and when attached to a green fluorescent protein (GFPuv). More importantly, we introduce a novel computational approach to predict the trend of the size and activity of the peptide-directed nanoparticles by estimating …

Improved Photodecarboxylation Properties In Zinc Photocages Constructed Using M‐Nitrophenylacetic Acid Variants, Austin K. Shigemoto, Avik Bhattacharjee, Erin E. Hickey, Hallee Jade Boyd, Theresa M. Mccormick, Shawn C. Burdette

Chemistry Faculty Publications and Presentations

The methoxy- and fluoro-derivatives of meta-nitrophenylacetic acid (mNPA) chromophores undergo photodecarboxylation with comparable quantum yields to unsubstituted mNPA, but uncage at red-shifted excitation wavelengths. This observation prompted us to investigate DPAdeCageOMe (2-[bis(pyridin-2-ylmethyl)amino]-2-(4-methoxy-3-nitrophenyl)acetic acid) and DPAdeCageF (2-[bis(pyridin-2-ylmethyl)amino]-2-(4-fluoro-3-nitrophenyl)acetic acid) as Zn2+ photocages. DPAdeCageOMe has a high quantum yield and exhibits other photophysical properties comparable to XDPAdeCage ({bis[(2-pyridyl)methyl]amino}(9-oxo-2-xanthenyl) acetic acid), the best perforiming Zn2+ photocage reported to date. Since the synthesis of DPAdeCageOMe is more straightforward than XDPACage, the new photocage will be a highly competitive tool for biological applications.

A Protein-Based Therapeutic Combination For The Treatment Of Hard-To-Heal Wounds, Graham L. Strauss

USF Tampa Graduate Theses and Dissertations

Chronic wounds present many clinical challenges in relation to the successful treatment and closure of the damaged tissue. Most current treatment methods focused on one or two aspects to drive wound closure, while most chronic wounds are multifactorial environments with many of those dependencies relying on the termination of one another to effectively gain tissue construction, closure, and full skin thickness and composition. Natural wound healing processes allude to potential biologics that can impede the chronic breakdown of tissue, while restoring deposition of new tissue, and effectively leading to a healed wound. Proteases secreted by the body’s immune system lay …

Large Area Projection Sintering Of Semicrystalline Polymers And Part Analysis Of The Printed Specimens, Taranjot Kaur

USF Tampa Graduate Theses and Dissertations

As the requirements posed to products have increased in recent years. The trend towards individualized serial products steps up the need for respective manufacturing techniques to be more and more flexible. Conventional techniques of serial production, such as injection molding, are unable to fully meet the requirements of this trend. Additive manufacturing techniques generate components directly from a CAD data set while requiring no specific mold, producing minimal waste, and reaching satisfactory geometric accuracy. This is how, as opposed to conventional techniques, they comply with these increased demands to processing technology. Over the last two decades, the research community has …

Synthesis And Catalytic Behaviors Of Sub-10nm Platinum Group Metal Nanocatalysts, Zixin Wang

Theses and Dissertations

Nanoparticles of platinum group elements(Pd, Pt, Rh, Ir, Ru and Os) exhibit intriguing catalytic behaviors that are sensitively dependent upon their particle dimensions, chemical compositions, and surface structures. Platinum group elementbased nanomaterials have been widely utilized for catalyzing a series of important chemical reactions, producing over 90% of chemicals and fuels and accounting for 35% of the world's GDP globally. Reducing the overall particle sizes of the catalysts to the sub-10 nm size regime not only effectively mitigates the cost issues associated with the noble metal-based materials, but also remarkably modifies the surface atomic coordinations and the electronic band energies, …

Small Molecule Activation By Dirhenium Carbonyl Complexes, Meenal Kaushal

Theses and Dissertations

The background of small molecule activation is discussed in Chapter 1. Carbon-hydrogen (C-H) bond activation and carbon-carbon (C-C) bond formation using transition metal complexes are explained using examples from the literature. It also includes the previous work done by Dr. Adams’ lab on C-H bond activation and zwitterions in metal carbonyl complexes.

The reaction of Re₂(CO)₈(µ-C₆H₅)(µ-H) with vinyl acetate yielding three new products has been discussed in Chapter 2. One of the products Re₃(CO)₁₃(µ-η² -C₂H₃), 2.3 further reacts with I₂ resulting in …

Mechanisms And Impact Of Hypoxia Regulated Inhibins In Cancer, Ben Allen Horst

Theses and Dissertations

Inhibins are heterodimeric ligands within the TGFβ superfamily, comprised of an α-subunit (INHA) and a β-subunit (either INHBA or INHBB) with emergent roles in cancer. Inhibins are biomarkers of disease burden and prognosis in a subset of cancers and utilize the coreceptors betaglycan (TGFBR3) and endoglin (ENG) for physiological or pathological outcomes. Previously, we found inhibin promotes angiogenesis in ovarian cancer however no mechanism of regulation for inhibin expression in cancer has been established. Hypoxia, a driver of tumor growth and metastasis, regulates angiogenic pathways that are targets for vessel normalization and ovarian cancer management. …

Evaluation Of The Energetic Factors In Crystalline Pharmaceuticals Using Solid-State Density Functional Theory And Low-Frequency Vibrational Spectroscopy, Margaret P. Davis

Dissertations - ALL

Due to the importance of maintaining stable and effective pharmaceutical solid doses, it is critical to study the variety of solid forms that active pharmaceutical ingredients can adopt including polymorphs, hydrates, and cocrystals. In this work, low-frequency vibrational spectroscopies and rigorous quantum mechanical simulations are combined to provide a new technique for characterizing and investigating pharmaceutically relevant polymorphs, hydrates, and cocrystals as well as a series of model cocrystals. Low-frequency spectra in the sub-200 cm-1 range provide not only unique and characteristic spectra for all of the systems explored here but, along with X-ray structural parameters, they offer a way …

Materials Discovery By Flux Crystal Growth: Synthesis, Structure Determination, Magnetic, And Optical Properties Of Complex Oxides, Oxychlorides, And Oxyfluorides, Darren Andrew Carone

Theses and Dissertations

Exploratory crystal growth has proven to be a successful technique in the synthesis of new compounds with desired properties. This method is very versatile and has various iterations, but results described herein were obtained through flux growth at high temperatures utilizing mixed alkali halide salts. The tunability of these reactions with respect to reactant ratios, reaction temperature, heating/cooling rates, metal precursors, and choice of flux allow for the exploration of phase spaces between a combination of elements and observation of significantly different products and/or structure types from minor tweaks.

Most of the research presented in this dissertation describes results that …

Crystal Growth Of Inorganic Halides And Oxide-Halides For Scintillation Applications And Radiation Detection, Gyanendra B. Ayer

Theses and Dissertations

Scintillators, materials which emit light when struck by high energy X-rays and y- rays, are extensively used in various fields including medical imaging, computed tomography, high-energy physics, and more recently in homeland security for the prevention of nuclear and radiological terrorism. While comparing with the traditional scintillators, which have long-term instability, high synthetic cost, toxicity, and hygroscopicity issues, metal halides have been reported to exhibit effective excitonic radioluminescence and greatly contribute in the field of scintillating applications and radiation detection. Currently, the mixed-anion oxide-fluorides have emerged as a prospective new class of scintillators, in which the mixed oxide-fluoride environment …

Novel Synthetic Strategies Toward Polyolefin-Grafted Nanoparticles, Richard Tran Ly

Theses and Dissertations

Surface functionalization of nanoparticles has proven to be a powerful and versatile strategy in the development of various materials with advanced properties. Polymer brush composition can range from complex copolymers to more simplistic polyolefin, and by functionalizing nanoparticle surfaces, mobility of distinct particles can then be tuned and, therefore, control over dispersion in a polymer matrix can be achieved. Presented in this dissertation are new synthetic strategies for the preparation of polymer nanocomposites.

The first chapter covers a novel synthetic strategy for ethylene/propylene-like copolymers grafted to silica nanoparticles. This approach utilizes Reversible Addition-Fragmentation Chain Transfer (RAFT) polymerization to promote living …

Uv- And Visible-Light Photopatterning Of Molecular Gradients Using The Thiol–Yne Click Reaction, Mark Mitmoen, Ofer Kedem

Chemistry Faculty Research and Publications

The rational design of chemical coatings is used to control surface interactions with small molecules, biomolecules, nanoparticles, and liquids as well as optical and other properties. Specifically, micropatterned surface coatings have been used in a wide variety of applications, including biosensing, cell growth assays, multiplexed biomolecule interaction arrays, and responsive surfaces. Here, a maskless photopatterning process is studied, using the photocatalyzed thiol–yne “click” reaction to create both binary and gradient patterns on thiolated surfaces. Nearly defect-free patterns are produced by first coating glass surfaces with mercaptopropylsilatrane, a silanizing agent that forms smoother self-assembled monolayers than the commonly used 3-mercaptopropyltrimethoxysilane. Photopatterning …

Method Of Hybrid Control Based Of Dynamic Objects Of Neuro-Fuzzy Inference, Noilakhon Yakubova

Karakalpak Scientific Journal

The Results of interaction of the work is development of a method of control that allows simplifying, automating and unifying the process of design of the hybrid systems which are a basis of modern automation. To achieve a definite purpose, a method of control of a technical object based on the construction of an adaptive system of neuro-fuzzy inference is developed. The objects of the system of neuro-fuzzy inference are the classical and neuro-fuzzy models of control. Information exchange between models is provided by means of the developed hybrid control system. The result of the interaction of the two models …

Application Of A Synergetic Approach To The Problem Of Synthesizing An Intelligent Control System For Chemical Reactors, Komil Usmanov

Karakalpak Scientific Journal

The article deals with the synthesis of effective algorithms for controlling a chemical reactor and developed a intelligent synergistic controller for a class of indefinite nonlinear dynamic systems. A synergetic control scheme is proposed for solving the control problem for nonlinear systems. Non-linear systems with configurations and parameters that change over time require a completely non-linear model and adaptive control scheme for a practical operating environment. The synthesis of control laws is performed by the method of analytical design of aggregated controllers (ADAR).

Development Of The Implementation Of Iot Monitoring System Based On Node-Red Technology, Anvar Kabulov, Inomjon Yarashov, Salamat Mirzataev

Karakalpak Scientific Journal

This article describes how to design and implement a process for storing environmental information in a database using the Internet of Things. The problems that need to be solved with the help of this IoT system are the growing demand for forecasts in the world, the demand of the world market for a new sustainable method of implementing the digitization environment through the Internet of Things. The design was implemented using Arduino, Node-Red and sensors, selected when choosing a component based on the required parameters and sent to the database for monitoring and processing. A study of previous work and …

Theoretical Features Of Foreign Systems Of Preschool Education, Ayjamal Bazarbaeva

Karakalpak Scientific Journal

This article analyzes the features of preschool education systems in foreign countries. The positive experience and features of some systems are highlighted. Comparison of domestic and foreign systems of preschool education is carried out.

Mechanism Of Sila- And Germafluorenes For Biological Applications, Shelby Jarrett

Dissertations

2,7-disubstituted silafluorenes and germafluorenes, originally designed for OLED applications, are a class of fluorescent dyes that have gained recent interest as probes for bioimaging and as biosensors to monitor cellular dynamics and interactions. Desirable biological probes absorb in the visible region, have high extinction coefficients, high quantum yield and excellent photostability. Here, their spectral properties are investigated under aqueous conditions for relevant biological applications. These molecules display intense blue fluorescence in the solid state and in solution, have high extinction coefficients, and exhibit appreciable solubility in aqueous solution. To better understand potential applications, the mechanism of fluorescence was investigated. It …

Table Of Contents

Journal of the South Carolina Academy of Science

No abstract provided.

Carbon Monoxide Oxidation On Model Planar Titania Supported Platinum Nanoparticles Catalyst, Jovine Emmanuel, Brian Hayden

Tanzania Journal of Science

A high-throughput (parallel) thermographic screening methodology was developed to enable the measurements of the particle size and support influence on heterogeneous catalysts. A high throughput screening chip has been used to establish the catalytic activity of titania supported platinum nanoparticles catalyst for CO oxidation reaction. The catalytic activity of Pt nanoparticles between 1.3 to 7.8 nm has been investigated for CO conversion at a pressure of 0.11 and 1.1 mbar with O2:CO ratio of 1:1 at 80 °C and 0.6, 1.1 and 2.4 mbar at O2:CO ratio of 1:1 at 240 °C. At these experimental conditions, there was an increase …

Co-Microencapsulation Of Ruellia Tuberosa L. And Cosmos Caudatus K. Extracts For Pharmaceutical Applications, Choirin Annisa, Sasangka Prasetyawan, Anna Safitri

Makara Journal of Science

This study aims to co-microencapsulate the Ruellia tuberosa L. and Cosmos caudatus K. extracts, with chitosan–sodium tripolyphosphate (Na-TPP) as coating material. α-Amylase inhibition and antioxidant assays were conducted to determine the potential of microcapsules used as antidiabetic agents. The microcapsules were manufactured under the influences of pH, Na-TPP concentration, and stirring time. The optimum microencapsulation conditions were selected based on the highest encapsulation efficiency. The optimum microencapsulation conditions were a pH of 4, Na-TPP concentration of 0.15% (w/v), and stirring time of 60 min. The microcapsules exhibited an IC₅₀ (inhibitory concentration) value of 223.64 ± 0.81 µg/mL and an …

Preparation Of Zn/Al-Chitosan Composite For The Selective Adsorption Of Methylene Blue Dye In Water, Risfidian Mohadi, Patimah Mega Syah Bahar Nur Siregar, Neza Rahayu Palapa, Aldes Lesbani

Makara Journal of Science

Layered double hydroxide (LDHs) are widely used adsorbents for methylene blue removal. However, LDHs have a perishable structure that cannot be used repeatedly. Modifying LDHs with chitosan produces a strong material with a large surface area for methylene blue adsorption. Adsorption conditions were optimized by determining the adsorption isotherms and the adsorbent regeneration process. Results showed that the adsorption process was balanced in 90 min with maximum adsorption capacities of 86.207 mg/g, 35.336 mg/g, and 98.039 mg/g for Zn/Al, chitosan, and Zn/Al-chitosan, respectively. The adsorption in this study followed the Freundlich isotherm model. Regeneration analysis of the adsorbent showed that …

Characterization Of Clay And Granite Dust Blends As Novel Materials For Energy Storage And Diffuser In Constructing Flat-Plate Solar Collector, Tajudeen Kolawole Ajiboye, Mustapha Olawale Fabiyi, Ndagi Mustapha, Sulaiman Abdulkareem

Tanzania Journal of Science

Sun is the main source of solar energy, and the energy it releases to the Earth’s surface in one hour is more than what the whole planet consumes in a year. This present work is about characterizing novel material that can be used as energy storage and diffuser in constructing flat plate solar collector. Materials used are clay and granite dust obtained from Okelele and Kulende Quarry sites, both in Ilorin, Kwara State, Nigeria. The materials were sun-dried; the clay crushed before the two materials were sieved into different particle sizes. They were thereafter blended into different ratios and then …

New Simple And Robust Method For Determination Of Polarity Of Deep Eutectic Solvents (Dess) By Means Of Contact Angle Measurement, Łukasz Cichocki, Dorota Warmińska, Justyna Łuczak, Grzegorz Boczkaj, Andrzej Przyjazny

Natural Sciences Publications

The paper presents a new method for evaluating the polarity and hydrophobicity of deep eutectic solvents (DESs) based on the measurement of the DES contact angle on glass. DESs consisting of benzoic acid derivatives and quaternary ammonium chlorides–tetrabutylammonium chloride (TBAC) and benzyldimethylhexadecylammonium chloride (16-BAC)—in selected molar ratios were chosen for the study. To investigate the DESs polarity, an optical goniometer and an ET(30)" role="presentation" style="box-sizing: border-box; max-height: none; display: inline; line-height: normal; font-size: 13.2px; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; color: rgb(34, 34, 34); font-family: Arial, …

Introduction Of Development And Application Technology Of Organic Additives For Acid Copper Electroplating, Hao-Bin Zou, Chao-Li Tan, Wei Xiong, Dao-Lin Xi, Bin-Yun Liu

Journal of Electrochemistry

Acid copper electroplating is one of the key technologies in buildup multilayer PCB (BUM-PCB) manufacture process and the most important technique to achieve electrical interconnection between any layer and high-density interconnection in a substrate. This article introduces the research focus of organic additives used in acid copper electroplating, and developing different kinds of micro-via filling copper electroplating technique applied in various scenarios, and some other technical problems from applications. First of all, according to the chronopotentiometric (CP) experiment results, the levelers with different polymeric molecular structures exhibited various responses of cupric deposition potential along with their increased concentrations, which is …