Digital Commons Network^™

Synthesis, Characterization, And Rna Reactivity Of Amino-Acid-Linked Cisplatin Analogues, Xun Bao

Wayne State University Dissertations

The essential role of ribosomal RNA (rRNA) in the cell life cycle is highlighted by protein synthesis; therefore, the ribosome is considered to be an ideal drug target. Ribosomal RNAs exhibit a high level of structural diversity. The well-known anticancer drug cisplatin was previously applied as a chemical probe of rRNA structure to determine solvent accessible purines (guanosine) in vivo and in vitro. Cisplatin accumulates faster on RNA than DNA, with less chance of repair. As such, designing new RNA-targeting Pt compounds is not only a promising direction for chemical-probing applications, but also for the design of anticancer drugs that …

Plant Species Rather Than Climate Greatly Alters The Temporal Pattern Of Litter Chemical Composition During Long-Term Decomposition, Yongfu Li, Na Chen, Mark E. Harmon, Yuan Li, Xiaoyan Cao, Mark A. Chappell, Jingdong Mao

Chemistry & Biochemistry Faculty Publications

A feedback between decomposition and litter chemical composition occurs with decomposition altering composition that in turn influences the decomposition rate. Elucidating the temporal pattern of chemical composition is vital to understand this feedback, but the effects of plant species and climate on chemical changes remain poorly understood, especially over multiple years. In a 10-year decomposition experiment with litter of four species (Acer saccharum, Drypetes glauca, Pinus resinosa, and Thuja plicata) from four sites that range from the arctic to tropics, we determined the abundance of 11 litter chemical constituents that were grouped into waxes, carbohydrates, …

Potential Antineoplastic Structural Variations Of Uracil Mustard (Uramustine) Retaining Cytotoxic Activity And Drug-Likeness Suitable For Oral Administration, Ronald Bartzatt

Chemistry Faculty Publications

Aims: To present 12 new variants of uracil mustard having drug-like properties and cytotoxic functional group, by utilizing uracil mustard (uramustine) as a lead compound. Utilize rigorous substructure and similarity of a molecular scaffold to determine drug like variants. Physicochemical properties determined indicate the variants have favorable drug-likeness.

Study Design: Conduct molecular database search utilizing features of substructure and similarity based upon uracil mustard. Place and Duration of Study: Department of Chemistry, Medicinal Chemistry Study Section, University of Nebraska at Omaha, Omaha Nebraska between January 2015 to March 2015.

Methodology: Uracil mustard consists of the pyrimidine derivative uracil, …

Preparation And Characterization Of Self-Assembled Monolayers And Mesoscale Protein Patterning, Panae Noomuna

Online Theses and Dissertations

Bottom-up approach was used to develop self-assembled monolayers of octadecyltrichlorosilane (OTS) and undecenyltrichlorosilane(UTS) on Si(100) wafer. Undecenyltrichlorosilane monolayer was oxidized at the vinyl terminal to generate a carboxylic acid group. Lysozyme protein was immobilized on the polar carboxylic acid group. The developed protein patterns were investigated using fluorescence microscopy. Lysozyme has an isoelectronic point of 11.35. At a pH below this value the protein is positively charged making it a good candidate for electrostatic adsorption on the negatively charge -COO- group. Fluorescence images confirm formation of lysozyme across the silicon wafer. The patterned Si(100) wafer can be used as a …

Nmr T₁ Studies Of Colloidal Unimolecular Polymer (Cup) Surface Water, Yousef Abobaker Dawib

Doctoral Dissertations

"This dissertation is subdivided into three topics: Experimental study of colloidal unimolecular polymer (CUP) hydration; probing of polymer chain dynamics by ¹³C solid state NMR technique; and the anticorrosive effect of 5-mercapto-1, 3, 4-thiadiazole-2(3H)-thione (MTT) derivatives.

The states of water in colloidal unimolecular polymer system were investigated by low field proton NMR. Bound and free water fractions were determined using spin-lattice relaxation measurements. A model equation was used to analyze the inversion recovery data.

The proton cross polarization and the pulse sequence for total spinning sideband suppression CP-TOSS NMR method were developed to determine the chain mobility of polymers …

Chemically Patterned Surfaces As Test Platforms To Study Magnetic And Solvent-Responsive Properties At The Nanoscale: Investigations Using Scanning Probe Microscopy, Shalaka Kulkarni

LSU Doctoral Dissertations

Chemically patterned surfaces were fabricated using a combination of molecular self-assembly and particle lithography to generate billions of nanostructures of organosilane self-assembled monolayers (SAMs). Monodisperse mesospheres were used as surface masks to prepare nanostructures on flat surfaces using the simple benchtop chemistry steps of mixing, centrifuging, evaporation, and drying. Periodic arrays of well-defined organosilane nanostructures serve as discrete surface sites for the selective deposition of polymers and magnetic nanoparticles.

In this dissertation, particle lithography approaches for surface patterning provide new directions for studying surface chemistry at the molecular-level using high resolution investigations with scanning probe microscopy (SPM). Atomic force microscopy …

Sign Me Up! Determining Motivation For High School Chemistry Students Enrolling In A Second Year Chemistry Course, Nilda N. Camarena

Theses and Dissertations - UTB/UTPA

A sample of 108 Pre-AP Chemistry students in Texas participated in a study to determine motivational factors for enrolling in AP Chemistry and University Chemistry. The factors measured were academic attitude, perceptions of chemistry, confidence level in chemistry, and expectations/experiences in the chemistry class. Students completed two questionnaires, one at the beginning of the year and one at the end. Four high school campuses from two school districts in Texas participated. Two campuses were traditional high schools and two were smaller magnet schools. The results from this study are able to confirm that there are definite correlations between academic attitudes, …

Evaluation And Application Of Instruments Measuring Spatial Ability And Attitude For College Chemistry Students, Xiaoying Xu

USF Tampa Graduate Theses and Dissertations

Student performance in college chemistry courses remains a concern for educators seeking to help improve the future STEM workforce. Besides math ability and prior chemistry knowledge, spatial ability and attitude toward chemistry have been considered as important factors influencing college chemistry performance. This work includes five studies and uses data collected from instruments to examine the relationships of these two factors - spatial ability and attitude - with student chemistry performance, and provides psychometric evidence for using the Purdue Visualization of Rotations test (ROT) and Attitude toward the Subject of Chemistry Inventory (ASCIv2) to measure these two factors, respectively, in …

Electron Transfer In Pnicogen Bond, Liangyu Guan

Masters Theses

Abstract is available for download as a separate file.

Diphenylethoxy-Substituted Metal-Free And Metallophthalocyanines As Potential Photosensitizer For Photodynamic Therapy: Synthesis And Photophysical And Photochemical Properties, Yusuf Yilmaz, Ali̇ Erdoğmuş, Muhammet Kasim Şener

Turkish Journal of Chemistry

The synthesis of a 4-(2,2-diphenylethoxy)phthalonitrile (1) and its organosoluble free base (2), zinc(II) (3), nickel(II) (4), and cobalt(II) (5) phthalocyanine derivatives is presented in this work. The novel complexes were characterized by elemental analyses and spectral data such as infrared, nuclear magnetic resonance, ultraviolet visible, and mass data. General tendencies were described for photophysics (fluorescence) and photochemistry (photodegradation and singlet oxygen quantum yields) of the free base and zinc(II) phthalocyanine derivatives in dimethylformamide. The quantum yield values of fluorescence (\Phi_F), singlet oxygen formation (\Phi_{\Delta}), and photodegradation (\Phi_d) for the zinc phthalocyanine were found to be 0.37, 0.48, and 9.12 \times …

Generation Of Diverse Molecular Complexity From Cyclooctatetraene, Mohamed Fawzy El Mansy

Dissertations (1934 -)

ABSTRACT

GENERATION OF DIVERSE MOLECULAR COMPLEXITY

FROM CYCLOOCTATETRAENE

Mohamed F. El Mansy, B.Sc, M.Sc.

Marquette University, 2014

The use of simple hydrocarbons as starting materials for the synthesis of complex molecules relies on efficient methods for oxidation, functionalization or rearrangement. For example, various researchers have explored cyclopentadiene or cycloheptatriene as precursors for the preparation of a wide variety of drug candidates, natural products and synthetic products. The purpose of this research is to explore methods to transform the simple hydrocarbon, cyclooctatetraene (COT) into complex target molecules.

Tricarbonyl (cyclooctatetraene)iron, readily prepared from COT, reacts with a variety of electrophiles to form …

Sublattice-Induced Symmetry Breaking And Bandgap Formation In Graphene, Ralph A. Skomski, Peter A. Dowben, M Sky Driver, Jeffery A. Kelber

Peter Dowben Publications

A reduction of symmetry from C_6v to C_3v leads to the opening of a band gap in the otherwise gapless semiconductor graphene. Simple models provide a fairly complete picture of this mechanism for opening a band gap and in fact can be discussed in terms of the tight-binding approximation, accurately resolving the wave-vector space to a very high accuracy. This picture is consistent with experiments that yield a band gap due to A and B graphene-site symmetry breaking due to substrate interactions.

Controlled Release Kinetics In Hydroxy Double Salts: Effect Of Host Anion Structure, Stephen Majoni, Jeanne M. Hossenlopp

Chemistry Faculty Research and Publications

Nanodimensional layered metal hydroxides such as layered double hydroxides (LDHs) and hydroxy double salts (HDSs) can undergo anion exchange reactions releasing intercalated anions. Because of this, these metal hydroxides have found applications in controlled release delivery of bioactive species such as drugs and pesticides. In this work, isomers of hydroxycinnamate were used as model compounds to systematically explore the effects of anion structure on the rate and extent of anion release in HDSs. Following intercalation and subsequent release of the isomers, it has been demonstrated that the nature and position of substituent groups on intercalated anions have profound effects on …

Lack Of Equivalence In The Elemental And Stable Isotope Chemistry Within The Sagittal Otolith Pair Of The Summer Flounder, Paralichthys Dentatus, Antranik Kajajian, Jason J. Schaffler, Cynthia M. Jones

OES Faculty Publications

In fish that are not bilaterally symmetrical, the left and right sagittae are often not symmetrical, exhibiting divergent growth patterns and mass, and may have differences in chemical composition. We investigated this in the asymmetrical summer flounder Paralichthys dentatus, collected from different nursery habitats along the US east coast. Significant differences were detected in otolith mass, δ¹³C, δ¹⁸O, Li:Ca, Mg:Ca, and Sr:Ca, and overall chemical signatures. These results refute the hypothesis of left-right equivalence that is prevalent for bilaterally symmetrical fishes. We tested whether a specific side was better suited for classification. The best models …

The Impact Of Multiple Nursery Areas On The Population Structure Of Atlantic Menhaden, Brevooria Tyrannus, Kristen A. Anstead

OES Theses and Dissertations

Understanding the population structure and patterns of connectivity in marine fishes is essential when making predictions about a species' resiliency and persistence in an increasingly changing environment. The Atlantic Menhaden Brevoortia tyrannus is a clupeid that plays a critical role in the marine food web and supports one of the largest fisheries on the US East Coast. In addition to a decrease in overall numbers and spawning stock biomass, recruitment levels have remained low since the 1990s. Menhaden use numerous estuaries along the Atlantic coast for juvenile development before recruiting to the adult population and the contribution of each of …

Reactive Pathways In The Chlorobenzene–Ammonia Dimer Cation Radical: New Insights From Experiment And Theory, Scott A. Reid

Chemistry Faculty Research and Publications

Building upon our recent studies of noncovalent interactions in chlorobenzene and bromobenzene clusters, in this work we focus on interactions of chlorobenzene (PhCl) with a prototypical N atom donor, ammonia (NH₃). Thus, we have obtained electronic spectra of PhCl···(NH₃)_n (n = 1–3) complexes in the region of the PhCl monomer S₀ −S₁ (ππ*) transition using resonant 2-photon ionization (R2PI) methods combined with time-of-flight mass analysis. Consistent with previous studies, we find that upon ionization the PhCl···NH₃ dimer cation radical reacts primarily via Cl atom loss. A second channel, HCl loss, is …

Characterization Of The Gas-Sensing Protein Cooa, Teryn Gehred, Jessica Lyza

Symposium on Research and Creative Expression (SORCE)

This research aims to characterize the binding specificity of heme proteins to various gas signal molecules. Heme proteins in the gas-sensing family bind to specific gas signal molecules, causing a certain biological function to be activated or deactivated. In this study, variants of the carbon monoxide sensing heme protein CooA from the bacteria R.rubrum and C. hydrogenoformans are compared. Key differences in signal binding specificity and heme environment configuration will be investigated. This is done by using site-directed mutagenesis to alter the heme environment, isolating the CooA proteins through protein purification, and analyzing the isolated products through DNA binding assays. …

Identification And Differentiation Of Tier 1 Bacterial Agents Using Gas Chromatography-Mass Spectrometry, Dan Li

Theses and Dissertations

A simple method was developed for detection and differentiation of five Tier 1 bacterial agents, including Bacillus anthracis, Francisella tularensis, Yersinia pestis, Burkholderia pseudomallei and Burkholderia mallei as well as their closely related near neighbors by gas chromatography-mass spectrometry (GC-MS). Generally, different classes of compounds can be used as biomarkers for biowarfare agent detection, including nucleic acids (i.e., DNA or RNA), proteins (i.e., antibodies), carbohydrates (i.e., sugars), lipopolysaccharides, lipids (i.e., fatty acids) and small molecules. One-step thermochemolysis (TCM) was developed to provide GC-MS detectable biomarker signatures, including sugars, fatty acids and small molecules. Solid phase micro-extraction (SPME) was used for …

Climate Evolution Of The Antarctic Peninsula Over The Last 1,000 Years : An Environmental Magnetism Analysis Of Two High Resolution Sediment Cores, Brendan Reilly

Theses, Dissertations and Culminating Projects

Two marine sediment cores from very different depositional environments, off the coast of western and northeastern Graham Land, Antarctic Peninsula (AP), record high resolution climatic records of the last 1,000 years. This study finds evidence in the sedimentary magnetic signature for a regional shift from warmer to colder climatic conditions around 1100-1400 AD. The first core, from middle Barilari Bay, western AP, displays a shift from seasonally open marine conditions to sub/proximal ice shelf ca. 1100 AD, with evidence for multiple grounding line advances in the magnetic mineral distributions during the first half of the last millennium. Prior to the …

Where Does The Water Come From? A Temporal Geochemical Characterization Of Water Sources In The Lives Of Storms, Mallory Ringham

Renée Crown University Honors Thesis Projects - All

An analysis of the ion chemistry, δ¹⁸O, and δ²H values of precipitation may allow for the characterization of their water sources. As water evaporates, it retains a signature of its source in the ions that it carries and in the amount of fractionation of the oxygen and hydrogen isotopes. Precipitation samples for coastal, lake effect, and continental sources were collected over the months of October- January in Syracuse, New York throughout the duration of each storm, including one hurricane, one thunderstorm, two lake effect snowstorms, and seven rain events. These samples were run through IC, ICP-OES, …

The Production Of Organic Nitrates In Portland Oregon And The Columbia River Gorge, Holly Ann Neill

Dissertations and Theses

This work studied the production of aerosol-phase organic nitrates in both Portland and the Columbia River Gorge (CRG). Ozone and NO_x species were investigated for correlation with organic nitrate aerosol, as they function as precursors to the production of organic nitrates. These ambient gas-phase measurements were collected in the same locations as high-volume (Hi-Vol) filters samples, in an urban and rural gorge setting to investigate correlations at the origin of the pollution plume and downwind. A novel Soxhlet extraction method for Hi-Vol filters was developed based on literature and EPA standard methods. Analysis for nitrate production was done by …

(Nhc)-Pd(Ii) Complexes With Hydrophilic Nitrogen Ligands: Catalytic Properties In Neat Water, Hayati̇ Türkmen, Lütfi̇ye Gök, İbrahi̇m Kani̇, Beki̇r Çeti̇nkaya

Turkish Journal of Chemistry

The cleavage reactions of the dimers [(NHC)PdX_2]_2 with hydrophilic N-donors, L, afforded the mixed-ligand complexes of the type trans-[(NHC)LPdX_2] (X = Cl or Br; NHC = 1,3-dialkylbenzimidazol-2-ylidene (BIm) or bis(imino)acenaphthene-annulated bis(2,6-diisopropylphenyl)imidazol-2-ylidene (BIAN-IPr); L = diethanolamine (DEA), morpholine (MOR), and 3-pyridinecarboxylic acid (3-PCA)). The new complexes (1--3) were characterized by elemental analysis and spectroscopic methods and the molecular structure of 1a was determined by X-ray diffraction studies. These complexes were applied in the Suzuki--Miyaura cross-coupling reaction of phenylboronic acid with aryl halides in neat water. The activities of catalysts were monitored by gas chromatography--flame ionization detector and nuclear magnetic resonance. Whereas …

Effect Of Laser Ablation Depth In Otolith Life History Scans, Renée R. Hoover, Cynthia M. Jones

OES Faculty Publications

Life history scans of fish otoliths are bringing new insight into the structure, connectivity, and movement of fish populations. Data obtained from such scans, however, possess in-herent limitations that have not yet been fully addressed or understood. For example, several investigators have noted delays in otolith elemental uptake that do not appear to reflect habitat exposure. We hypothesized that the 3-dimensional structure of otoliths may produce sampling artifacts in the results obtained from laser ablation scans. To test this hypothesis, we sampled sagittal otoliths from juvenile Atlantic croaker Micropogonias undulatus with laser ablation inductively coupled plasma mass spectrometry to obtain …

Trace-Element And Physical Response To Melt Percolation In Summit (Greenland) Snow, Gifford J. Wong, Robert L. Hawley, Eric R. Lutz, Erich C. Osterberg

Dartmouth Scholarship

Surface melt on a glacier can perturb the glaciochemical record beyond the natural variability. While the centre of the Greenland ice sheet is usually devoid of surface melt, many high- Arctic and alpine ice cores document frequent summertime melt events. Current hypotheses interpreting melt-affected ice-core chemistry rely on preferential elution of certain major ions. However, the precise nature of chemistry alteration is unknown because it is difficult to distinguish natural variability from melt effects in a perennially melt-affected site. We use eight trace-element snow chemistry records recovered from Summit, Greenland, to study spatial variability and melt effects on insoluble trace …

Computational Chemistry Capacity Building In An Underprivileged Context: Challenges, Outcomes And Perspectives, L Mammino

Tanzania Journal of Science

Computational chemistry is a fast developing branch of modern chemistry, focusing on the study of molecules to enable better understanding of the properties of substances. Its applications comprise a variety of fields, from drug design to the design of compounds with desired properties (e.g., catalysts with specific actions) and to ample overlaps with nanotechnology. However, despite its relevance, the presence of computational chemistry research in Sub-Saharan Africa is still scarce, practically absent in many institutions. Bridging the gap with the other continents requires the identification of capacity building options that may enable a rapid growth. The recent experience at the …

Synthesis Of Novel Alkaline Earth Tosylate Complexes Through Donor Studies, Adam J. Brooks

Renée Crown University Honors Thesis Projects - All

Salt metathesis has become a critical reaction pathway in organometallic chemistry; however, for alkaline earth metals this process is hindered by the need of highly pure and expensive metal iodides as starting materials. This contribution highlights recent attempts to identify inexpensive reagents for salt metathesis. Alkaline earth-tosylates can be prepared cost effectively using p-toluenesulfonic acid in one-pot reactions in water. The coordinated water molecules can be removed by gentle heating under vacuum. The anhydrous tosylates, however, have major solubility limitations as the result of extensive aggregation networks. The goal of this study was to increase the solubility of the tosylates …

Evaluation Of A Wide Rim Phosphorylated Calix[4]Arene's Properties As A Sensory Molecule In An Er(Iii)-Pvc Membrane Sensor, Abbas Ali Zamani, Massoumeh Parinejad, Fataneh Jamali, Mohammad Reza Yaftian, Dominique Matt

Turkish Journal of Chemistry

This study concerns the evaluation of ionophoric properties of a functionalized calix[4]arene, named 5,17-bis(diphenylphosphinoyl)- 25,26,27,28-tetrapropoxycalix[4]arene (Calix), by its application as a sensing material in an erbium(III)-PVC membrane potentiometric sensor. A membrane formed by 30% PVC, 65% dioctyl phthalate (DOP) as plasticizing solvent mediator, 2% sodium tetraphenyl borate (NaTPB) as ion excluder, and 3% of Calix as ionophore shows the best performance of the sensor. The prepared sensor presents a nearly Nernstian response (a slope of 20.0 \pm 0.5 mV/decade) over a concentration range of 1 \times 10^{-7}--1 \times 10^{-3} M of erbium ions, with a limit of detection of 3.8 …

A Century Of Chemistry Instruction At The College In Arlington: 1895-1995 (A Memoir And Scrapbook), Thomas James Cogdell

Chemistry & Biochemistry Faculty Publications - Archive

No abstract provided.

Ferritin Diversity: Mechanistic Studies, Disease Implications, And Materials Chemistry, Robert Joseph Hilton

Theses and Dissertations

The study of ferritin includes a rich history of discoveries and scientific progress. Initially, the composition of ferritin was determined. Soon, it was shown that ferritin is a spherical, hollow protein. Eventually, over several decades of research, the structure and some function of this interesting protein was elucidated. However, the ferritin field was not completely satisfied. Today, for example, researchers are interested in refining the details of ferritin function, in discovering the role of ferritin in a variety of diseases, and in using ferritin for materials chemistry applications. The work presented in this dissertation highlights the progress that we have …

Effect Of Freshman Chemistry On Student Performance In Sophomore Engineering Courses, Michael A. Collura, Shannon Ciston, Nancy Ortins Savage

Chemistry and Chemical Engineering Faculty Publications

The role of first year chemistry courses in engineering programs varies somewhat across programs and disciplines. Clearly most engineering majors will encounter chemistry topics of a general nature in some of their upper-level course work. The purpose of requiring chemistry in the first year, however, goes well beyond learning chemical concepts. As a quantitative science, chemistry requires the use of math, principally algebra, on a regular basis in solving various problems. Students should gain an appreciation of the importance of units in solving problems should come to understand the difference between implicit and explicit properties and should develop other quantitative …