Chemistry Commons^™

Functional Supramolecular Materials And The Design And Synthesis Of Triple Negative Breast Cancer Pharmaceuticals, Dustin Wayne Goodlett

Theses and Dissertations

Organization of benzophenone in the solid-state facilitates the formation of persistent and regenerable radicals at room temperature upon exposure to light. Upon incident irradiation, the triplet sensitizer rapidly undergoes intersystem crossing to a triplet excited state. Structural investigation of four distinct benzophenone supramolecular assemblies gives insight into the different processes these materials can undertake once in the triplet excited state such as persistent radical formation, phosphorescence, and self-quenching.

Self-assembly of brominated triphenyl amine bis-urea macrocycles forms a host material with unidirectional pores. Separations of xylene constitutional isomers via adsorption within this crystalline host material at ambient temperature are shown to …

Bibliometric Analysis Of Named Entity Recognition For Chemoinformatics And Biomedical Information Extraction Of Ovarian Cancer, Vijayshri Khedkar, Charlotte Fernandes, Devshi Desai, Mansi R, Gurunath Chavan Dr, Sonali Tidke Dr., M. Karthikeyan Dr.

Library Philosophy and Practice (e-journal)

With the massive amount of data that has been generated in the form of unstructured text documents, Biomedical Named Entity Recognition (BioNER) is becoming increasingly important in the field of biomedical research. Since currently there does not exist any automatic archiving of the obtained results, a lot of this information remains hidden in the textual details and is not easily accessible for further analysis. Hence, text mining methods and natural language processing techniques are used for the extraction of information from such publications.Named entity recognition, is a subtask that comes under information extraction that focuses on finding and categorizing specific …

Toward Understanding The Origin Of Mass-Independent Fractionation In Sulfur Allotropes And In Ozone, Igor Gayday

Dissertations (1934 -)

Mysterious isotope effects, found in atmospheric ozone, cannot be explained by the standard mass-dependent statistical model. Similar mass-dependent isotope effects were also uncovered in sulfur deposits older than 2 billion years. In an effort to pinpoint possible reasons of these isotope effects, we build a theoretical description of the recombination reactions in sulfur allotropes and in ozone. No potential energy surface exists for the sulfur allotropes, so electronic structure calculations are also required. Ab initio calculation of two dimensionally reduced (2D and 3D) models of the potential energy surface for the tetrasulfur molecule at CCSD(T)-F12 and MRCI levels of theory …

Design And Synthesis Of Selective Estrogen Receptor Agonists, Edward Edward Wetzel

Dissertations (1934 -)

Estrogens are hormones that regulates many different physiological functions. A decline in estrogen leads to significant issues that decrease the quality of life. Past treatments of menopausal symptoms included the administration of estrogen. However, side effects such as an increased risk of breast cancer, made this an unattractive therapeutic option. When a new estrogen receptor (ERβ) was discovered, it provided new hope for hormone replacement therapy (HRT). ERβ was shown to inhibit tumor growth, whereas ERα regulates breast cancer proliferation in certain types of breast cancer. The therapeutic benefits of targeting ERβ are vast; herein we focus on the benefits …

Synthetic And Mechanistic Studies Of Ruthenium Catalyzed C-C, C-H And C-N Bond Activation Reactions, Nuwan Asanka Pannilawithana

Dissertations (1934 -)

Transition metal-catalyzed selective CH, CC and CN bond activation reactions represent a challenging and synthetically important field in organic chemistry. In particular, transition-metal catalytic unreactive bond activation protocols are applicable in various stereoselective and atom economical complex organic molecule synthesis. Recently, significant research efforts have been made for utilizing catalytic CH and CC bond cleavage methods in the further development of commercially valuable pharmaceuticals and agrochemicals. The well-defined cationic Ru–H complex was found to be an effective catalyst for mediating the coupling reaction of 1,2-disubstituted indoles with α,β-unsaturated aldehydes and ketones, in which the regioselective Cα–Cβ activation of the carbonyl …

Scope And Mechanistic Studies Of Ruthenium Catalyzed C-N Bond Activation Reactions, Pandula Taepith Kirinde Arachchige

Dissertations (1934 -)

Primary aliphatic amines which are ubiquitous in natural products, traditionally considered as inert to substitution reactions. Recent studies clearly demonstrated that the aliphatic deaminative coupling chemistry can be used to make valuable scaffolds through C–N bond activation on transition metal complexes. The catalytic system generated in situ from the tetranuclear Ru–H complex with a catechol ligand (2-9/2-16) and independently synthesized ruthenium catecholate complex 2-11 was found to be effective for the direct deaminative coupling of primary amines. The catalytic system formed in-situ from the reaction of cationic Ru–H complex 2-10 with 3,4,5,6-tetrachloro-1,2-benzoquinone 2-12 was found to mediate a regioselective deaminative …

Kinetics Studies On Isomerization And Unimolecular Decay Processes Of The Criegee Intermediate, Methacrolein (Macr) Oxide, Hyun Kyung Lee , '21

Senior Theses, Projects, and Awards

Alkenes are one of the major components of hydrocarbons in our atmosphere. One of the most common alkenes in our atmosphere is isoprene (2-methyl – 1,3 – butadiene). Currently, it is known that isoprene ozonolysis can lead to the production of Criegee intermediates CH2OO, methacrolein (MACR) oxide, and methyl vinyl ketone (MVK) oxide. In part, we were interested in studying one specific Criegee intermediate, MACR oxide. The competition between the isomerization reactions and the unimolecular reactions became the focus of our study. Rate constants for the relevant reactions were calculated by implementing RRKM theory and using Master Equation modeling to …

Synthesis And Characterization Of Α-Diimine Complexes Of Aluminum, Judah B. Raab , '21

Senior Theses, Projects, and Awards

Conventional aluminum complexes are incapable of one- and two-electron redox chemistry. As a result, despite being the most abundant metal on Earth, aluminum is seldom used in redox catalysis—one of chemistry’s most impactful fields. We are motivated to break this barrier to provide a green alternative to the countless redox catalysts built around the toxic, mining-intensive platinum-group metals. To create aluminum complexes that do desirable redox chemistry, we coordinate redox-active α-diimine ligands to the metal center. These ligands are stable across multiple oxidation states, allowing for multi-electron redox chemistry for their aluminum complexes. This thesis will report the synthesis of …

Partial Oxidation Of Methane To Synthesis Gas Over Ni/Γ-Al₂O₃ Catalysts: The Effect Of The Structure And The Pre-Treatment Of The Support On The Catalysts’ Performance, Sheikh Tijan Jobe

Theses

Abundant natural gas is a potential source of more cost-effective energy and its effective utilization can significantly reduce the dependence on petroleum oil. Disadvantages of natural gas as a direct fuel include its low energy density by volume, and high cost of transportation, which resulted in its underutilization as an alternative energy source. Therefore, the conversion of methane to more easily-handled and value-added products is becoming a promising route for natural gas utilization. Compared to steam reforming of methane to syngas, which is the most commercially applied conversion process, partial oxidation is a more cost-effective promising route. While noble metals …

Fabrication Of Chemically-Functionalized 3dprinted Porous Scaffolds For Biomedical Applications, Eiman Hamed Alblooshi

Theses

Hard tissues, such as bone and teeth, are natural composites of collagen nanofibers that are reinforced by inorganic calcium phosphate Nano crystallites, in the form of nanocomposites. The interlocking between these components in hard tissues explains their unique characteristics. Bone is mainly classified into two major types; compact and cancellous depending on the extent of porosity. Fractures in the compact bone can be treated using bone fixation implants, such as rods, screws, and plates, or can be totally replaced by bone implants if complete substitution is required. Cancellous bone, on the other hand, is highly porous and its substitution with …

Levels Of Testosterone Esters In Camel Hair, Aysha Khalid Alraeesi

Theses

Doping and steroid use represent a serious threat to animal health and can even lead to their untimely and painful death. However, doping is an acute problem in today's animal racing world, particularly in camel racing. Testosterone and its ten esters (benzoate, valerate, isocaproate, hexahydrobenzoate, decanoate, undecanoate, laurate, enanthate, cypionate, and caproate) are of utmost importance because when they are administered to animals it is difficult to measure them efficiently. The levels of testosterone and its esters in camels and other animals are typically determined using urine and blood tests. The aim of this study was to develop and validate …

Food Security As A Factor Of Sustainable Development Of The Country, Timur Nurimbetov

Karakalpak Scientific Journal

The article examines the state of the food market and the trends in ensuring the country’s food security. The article also analyzes the regional characteristics of the agricultural products market in the Republic of Karakalpakstan. The saturation level of regional food markets has been studied. Scientific conclusions and practical recommendations on the supply of food to the population have been made.

Influence Of Laterial State Of Pair Impurity Complex On Recombination Processes In Semiconductors, L Yu Leyderman, R A. Ayukhanov, Abat Uteniyazov, E S. Esenbaeva, Sh X. Annayeva

Karakalpak Scientific Journal

The paper analyzes the question of the possible influence of the lateral state of a paired impurity complex on the recombination processes. It is shown that the lateral state of the paired impurity complex does not affect the recombination processes of nonequilibrium carriers - they go through that component of the impurity complex that exchanges carriers with both bands (in this particular case, through the component). The second component of the complex () can apparently play some role in the processes of carrier attachment.

Exploring The Roles Of Herc2 And The Nedd4l Hect E3 Ubiquitin Ligase Subfamily In P53 Signaling And The Dna Damage Response, Nicholas A. Mathieu, Rafael H. Levin, Donald E. Spratt

Chemistry

Cellular homeostasis is governed by the precise expression of genes that control the translation, localization, and termination of proteins. Oftentimes, environmental and biological factors can introduce mutations into the genetic framework of cells during their growth and division, and these genetic abnormalities can result in malignant transformations caused by protein malfunction. For example, p53 is a prominent tumor suppressor protein that is capable of undergoing more than 300 posttranslational modifications (PTMs) and is involved with controlling apoptotic signaling, transcription, and the DNA damage response (DDR). In this review, we focus on the molecular mechanisms and interactions that occur between p53, …

Polymer Based Triboelectric Nanogenerator For Cost‐Effective Green Energy Generation And Implementation Of Surface‐Charge Engineering, Diana Lopez, Aminur Rashid Chowdhury, Abu Masa Abdullah, Muhtasim Ul Karim Sadaf, Isaac Martinez, Brishty Deb Chowdhury, Serena Danti, Christopher J. Ellison, Karen Lozano, Mohammed Jasim Uddin

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Performance of triboelectric nanogenerators for harvesting mechanical energy from the ambient environment has been limited by structural complexity, cost-effectiveness, and mechanical weakness of materials. Herein, a cost-effective vertical contact separation mode triboelectric nanogenerator using polyethylene (PE) and polycarbonate (PC) in a regular digital versatile disc is reported. This cost-effective nanogenerator with simplified structures is able to generate an open-circuit voltage of 215.3 V and short-circuit current of 80 μA. The effects of the distance of impact and the air gap between the triboelectric layers have also been tested from 3 to 9 cm, and 0.25 to 1 cm, respectively. It …

Organization Of Compact Spinning Technology In Textile Clusters, Baxtiyar Aralbaevich Paluanov, Abdimalik Pirmatovich Pirmatov

Karakalpak Scientific Journal

The article proposes a system of continuous supply of raw cotton in continuous spinning technology and methods of maximizing the preservation of the natural properties of the fiber and obtaining high-quality yarn.

Imaging Of Neurotransmitters And Small Molecules In Brain Tissues Using Laser Desorption/Ionization Mass Spectrometry Assisted With Zinc Oxide Nanoparticles., Chaochao Chen, Steven R Laviolette, Shawn N Whitehead, Justin B Renaud, Ken K-C Yeung

Chemistry Publications

Inorganic nanostructured materials such as silicon, carbon, metals, and metal oxides have been explored as matrices of low-background signals to assist the laser desorption/ionization (LDI) mass spectrometric (MS) analysis of small molecules, but their applications for imaging of small molecules in biological tissues remain limited in the literature. Titanium dioxide is one of the known nanoparticles (NP) that can effectively assist LDI MS imaging of low molecular weight molecules (LMWM). TiO₂ NP is commercially available as dispersions, which can be applied using a chemical solution sprayer. However, aggregation of NP can occur in the dispersions and the aggregated NP …

Multi-Institutional Study Of Self-Efficacy Within Flipped Chemistry Courses, Nicole Naibert, Kerry D. Duck, Michael M. Phillips, Jack Barbera

Chemistry Faculty Publications and Presentations

Active learning environments have been shown to be beneficial for student learning; however, including such activities can be limited by the class time available. One method that can provide more opportunities for active learning during face-to-face class time is the flipped learning approach. However, studies on the impacts of flipped learning environments on student motivation are limited. Therefore, in this multi-institutional study, general chemistry students enrolled in flipped courses at three institutions responded to measures of self-efficacy and self-regulatory strategies. The results from these measures were used to evaluate how students’ academic self-efficacy (ASE) and chemistry self-efficacy (CSE) changed over …

Adsorption And Transport Of Colloids At Interface And In Bulk, Jingyun Lee

LSU Doctoral Dissertations

Colloids are suspensions of microscopic insoluble particles dispersed in a continuum phase such as liquid or gas. Colloids are found in our everyday life from food and cosmetic industries to pharmaceutical and biomedical applications. Depending on a global minimum of the free-energy landscape, colloidal suspensions can be classified as two major classes: equilibrium or active colloidal system. This Ph.D dissertation presents strategies to engineer equilibrium self-assembled structures and out-of-equilibrium active matter using various interparticle forces.

First, we introduce the means to promote the equilibrium self-assembled structures driven by adsorption of colloids at interface. Typically, adsorption of colloids at interface is …

Optimizing Fluorescence Pmt Gain And Excitation Wavelength For Hplc Dl-Amino Acid Detection, Daranthea Amanda Atmadja, Aaron Jacobs

Honors Scholars & Undergraduate Research Poster Symposium Programs

Amino acids exist as enantiomers that can be separated and detected using HPLC-FLD. An optimal PMT gain and wavelength of excitation must be determined to lower the limit of detection (LOD) and quantitation (LOQ) as increasing the PMT gain amplifies the signal on the HPLC-Spectra. The HPLC-FLD spectra of OPA-IBLC derivatized histidine was measured at PMT gain 5 and 7 for the excitation wavelengths of 340-, 260-, and 240- nm. Hence, the optimal excitation wavelength and PMT gain can be determined by comparing the fluorescence spectra.

Past, Present, And Future– A Review Of Berrien County Water And Great Lakes Water Resources And Quality, Jongwan Bae

Honors Scholars & Undergraduate Research Poster Symposium Programs

The decrease in water quality for environmental and drinking water has been prevalent in the Great Lakes region, where industrialization, agricultural development, and population increase have contributed substantially. Looking through historical reports and the present, the degradation in water quality will likely continue. Our research intends to use inductively coupled plasma atomic emission spectroscopy to create a methodology to quantitatively detect various heavy metals and other elements from any water source. Current research has been on the determination of a niche in water testing and the creation of an infographic, as well as data of simple water samples.

Copper (Ii) Sequestration By Pamam Dendrimers In Tap Water, Hannah Castillo

Honors Scholars & Undergraduate Research Poster Symposium Programs

Dendrimers are nanomaterials that are widely studied for a variety of applications because of their distinctive properties. One such property of, specifically, the generation 2-PAMAM Dendrimer is its particular affinity for copper (II) ions. This could be influential in selective heavy metal extraction, particularly in contaminated water. Our research aims to test the sequestration and selectivity of PAMAM dendrimers with amine surface groups for copper (II) ions in a chemical environment with interfering species, such as tap water, using Inductively Coupled Plasma spectroscopy. Ongoing research has involved developing methods for dendrimer extractions and creating calibration curves for standards to ensure …

Determination Of Atrazine In Glacier Creek Using Gas Chromatography-Mass Spectrometry, Spencer Witte

UNO Student Research and Creative Activity Fair

Atrazine is a commonly used herbicide in agriculture that has been shown to cause adverse health-effects on biological organisms. Glacier Creek Preserve (GCP), a prairie preserve near Omaha, NE, contains restored prairie and agricultural land uses within a single watershed. Surface water samples were collected at various locations of GCP from May to July to quantify atrazine concentrations. Sample preparation included filtering with a 0.45 micron filter and solid-phase extraction (SPE) with a reversed-phase cartridge. The analyte was eluted off the cartridge with ethyl acetate and analyzed by gas chromatography-mass spectrometry (GC/MS). Quantitation was performed with an internal standard calibration …

Data For "Subtype-Selective Positive Modulation Of Sk Channels Depends On The Ha/Hb Helices", Miao Zhang, Meng Cui

Pharmacy Faculty Data Sets

In the activated state of small-conductance Ca²⁺-activated potassium (SK) channels, calmodulin interacts with the HA/HB helices and the S4-S5 linker. CyPPA potentiates SK2a and SK3 channel activity but not the SK1 and IK subtypes. Here, we report that the subtype-selectivity of CyPPA relies on the HA/HB helices. Mutating residues in the HA (V420) and HB (K467) helices of SK2a channels to their equivalent residues in IK channels diminished the potency of CyPPA. CyPPA elicited prominent responses on mutant IK channels with an arginine residue in the HB helix substituted for its equivalent lysine residue in the SK2a channels …

Molecular Design Of Three-Dimensional Metal-Free A(Nh4)X3 Perovskites For Photovoltaic Applications, Jie Bie, Dai-Bei Yang, Ming-Gang Ju, Qiang Pan, Yu-Meng You, Wei Fa, Xiao Cheng Zeng, Shuang Chen

Xiao Cheng Zeng Publications

The intense research activities on the hybrid organic−inorganic perovskites (HOIPs) have led to the greatly improved light absorbers for solar cells with high power conversion efficiency (PCE). However, it is still challenging to find an alternative lead-free perovskite to replace the organohalide lead perovskites to achieve high PCE. This is because both previous experimental and theoretical investigations have shown that the Pb²⁺ cations play a dominating role in contributing the desirable frontier electronic bands of the HOIPs for light absorbing. Recent advances in the chemical synthesis of three-dimensional (3D) metal-free perovskites, by replacing Pb²⁺ with NH₄^{+ …}

Pressure- And Temperature-Dependent Inelastic Neutron Scattering Study Of The Phase Transition And Phonon Lattice Dynamics In Para-Terphenyl, Qingan Cai, Michael Mcintire, Luke L. Daemen, Chen Li, Eric Chronister

Chemistry and Biochemistry Faculty Research

Inelastic neutron scattering has been performed on para-terphenyl at temperatures from 10 to 200 K and under pressures from the ambient pressure to 1.51 kbar. The temperature dependence of phonons, especially low-frequency librational bands, indicates strong anharmonic phonon dynamics. The pressure- and temperature-dependence of the phonon modes suggest a lack of phase transition in the region of 0-1.51 kbar and 10-30 K. Additionally, the overall lattice dynamics remains similar up to 200 K under the ambient pressure. The results suggest that the boundary between the ordered triclinic phase and the third solid phase, reported at lower temperatures and higher pressures, …

Two-Electron Donating Phenothiazines And Use Thereof, Susan A. Odom, Aman Preet Kaur, Matthew D. Casselman, Nuwan Harsha Attanayake

Chemistry Faculty Patents

Compounds for use as electrolyte in a non-aqueous redox battery are provided, including an N-substituted phenothiazine compound according to the formula: (see patent for formula.)

R' is alkyl and R is selected from alkyl, aryl, alkylaryl, alkoxyaryl, alkylcarboxyl, arylcarbonyl, haloalkyl, perfluo- roalkyl, glycol, polyether, haloaryl, a negative electrolyte, a polymerizable unit, and a polymer.

Steep Sulfur Gradient In Cztsse Solar Cells By H2s-Assisted Rapid Surface Sulfurization, Teoman Taskesen, Devendra Pareek, Dirk Hauschild, Alan Haertel, Lothar Weinhardt, Wanli Yang, Timo Pfeiffelmann, David Nowak, Clemens Heske, Levent Gütay

Chemistry and Biochemistry Faculty Research

Sulfur/selenium grading is a widely used optimization strategy in kesterite thin-film solar cells to obtain a bandgap-graded absorber material and to optimize optical and electrical properties of the solar-cell device. In this work, we present a novel approach to introduce a [S]/([S] + [Se]) grading for Cu ZnSn(S,Se) solar cells. In contrast to commonly used methods with slow process dynamics, the presented approach aims to create a fast sulfurization reaction on the surface of pure selenide kesterite absorbers by using highly reactive H S gas and high sulfurization temperatures in a rapid flash-type process. With a combination of X-ray photoelectron …

Noncovalent Bonds Through Sigma And Pi-Hole Located On The Same Molecule. Guiding Principles And Comparisons, Wiktor Ziekiewicz, Mariusz Michalczyk, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

Over the last years, scientific interest in noncovalent interactions based on the presence of electron-depleted regions called σ-holes or π-holes has markedly accelerated. Their high directionality and strength, comparable to hydrogen bonds, has been documented in many fields of modern chemistry. The current review gathers and digests recent results concerning these bonds, with a focus on those systems where both σ and π-holes are present on the same molecule. The underlying principles guiding the bonding in both sorts of interactions are discussed, and the trends that emerge from recent work offer a guide as to how one might design systems …

Telsam-Target Protein Fusions Can Form Diffraction-Quality Crystals Without Direct Inter-Polymer Contacts, Moriah Longhurst

Undergraduate Honors Theses

X-ray diffraction is a robust method for determining the detailed 3D structures of specific proteins. However, this requires the formation of well-ordered protein crystals, a process that is time-consuming, expensive, and only has about a 10-30% success rate. New methods are needed to enable the efficient crystallization of challenging proteins. One such technique is explored here, which utilizes a protein polymer (the sterile alpha motif domain of the human protein translocation Ets leukemia, or TELSAM) as a crystallization chaperone to form a more ordered crystal lattice of target proteins and drive crystallization. This method was successfully used to crystallize, collect …